20 Vartarg - Case Forming from 223 (Irregularities and Testing)

[Oso]

Buying already formed brass is definitely worth considering, either from one of the niche specialty stores or one of the members on the Forum who also make brass for sale. This is what I initially did just to shoot the rifle when it came back from gunsmith. If you like reloading and also get some satisfaction with being self-sufficient then case-forming for your rifle will bring you a smile.

Forming the cases really isn't that bad of a process, especially if you are using new brass. In which case you are really only dealing with deburring the flashhole and maybe uniforming the primer pockets (depending upon brand of brass), both of which are quickly accomplished with aid of power drill.

After working out the 17-222 case forming process, I got to tell you that the 20VTG case forming process is a breeze!!!

 

[Just Say Moe]

My **amateur beginner** experience with range pickup brass was to anneal the bodies and then add Imperial lube to the body only to reduce case wrinkling. I still had 30% fail rate but what the heck it was free. Don't know how but it worked.

 

[mefizto]

Greetings all,

it must be beginner's luck with me - at least during the first step of forming .221 from .223 cases. Range pickup cases were cleaned and de-primed. Without any additional processing, i.e., annealing, I applied a light coat of mink oil to the bodies only and fed the cases into Redding .221 full body die. I tried to (1) push the case about 1/2 way, then back up, rotate the case 180 deg and finish the forming and (2) form in a single stroke, but I cannot see any differences.

Apart from .223 cases I rejected upon initial inspection, I have 99+% yield.

In contemplating the next step, I measured a few cases. The reference Lapua cases have neck outside diameter .248 and inside diameter .221. The re-formed cases have neck outside diameter 0.253 and inside diameter .225. Thus the thickness of the brass is about the same. I measured the inside diameter by inserting machinist pin.

If I understand correctly, the next step, after cutting the cases to size, is to acquire a bushing die (Redding?) and appropriate bushing. Given the dimensions above, what size of bushings would you recommend?

Kindest regards,

M

 

[Oso]

Mefizto,

Most of the range brass that I was using for practice was previously fired through an AR15 so there are lots of minor nicks and dents on the cases. Anything that wasn't perfect I culled as a reject... a fair number of them only had minor superficial defect and would have fired without any issue. I was interested in a near-perfect output, similar to what I would expect to achieve forming with new factory cases.

I have the Redding Type-S Full Length Sizing Die in 20 Vartarg. As to your question about what bushing you might need...

.253" O.D. - .225" I.D. = .028" Total Wall Thickness ... divide by 2 sides and your neck wall thickness is .014"

.204" Bullet O.D. + .028" Neck Wall Thickness (2 sides) = .232" O.D. of Loaded Cartridge

You want to have .002"-.003" of neck tension: .231" - .002" = .230 Bushing or .229 Bushing

The neck dimension of your rifle's chamber may/may not require you to do neck turning to give the case adequate clearance. Have you measured the Neck O.D. of a case fired through the rifle. Ignoring brass spring-back, this measurement is a rough proxy for your chamber's neck diameter.

It is common to neck turn the formed cases to a wall thickness of .012" - .013". If you plan to do this then you will need to adjust your bushing to something like a .228" Bushing.

 

[mefizto]

Hi Oso,

thank you for the reply.

Like your cases, most of mine were also fired from AR15 and, likewise had marks, mostly about middle of the neck area and about 40% from the bottom. After cleaning and sorting the cases, I showed some examples to an experienced friend, and I mercilessly culled those with deeper marks on the bodies, since the marks on the neck ended at the portion that will be trimmed off.

Thank you very much for breaking the dimensional calculation, so even a moron like I can understand it.

Regarding the rifle chamber, I am approaching the problem backwards since I would prefer not to turn necks. Thus, I will first finish building the cases (I have sets of 5 for different head-stamps), to ascertain the consistency and, by extension, if come head-stamps should be avoided. Then I will specify a reamer for my barrel with the correct tolerance.

This leads me to two more questions. One, you mentioned turning the cases to 0.012 - 0.013 inch. What is the reason? Is the 0.014 inch too much? And if so, why does Lapua, which appears to be a prime manufacturer, build cases with such a thickness?

Two, what tolerance should I add to the build case dimension to specify a reamer?

Kindest regards,

M

P.S. it is literally more that two questions.

 

[Oso]

I am very much a novice with the whole case forming/neck turning activities. These are the things that I am learning and perfecting.

Based on everything that I have learned, both on this forum and Saubier, the most common chamber for 20 Vartarg has a neck diameter of .234". This is fairly tight chamber if loaded cartridge's neck O.D. is .232", which would only give .001" clearance on each side of neck. Depending upon the donor brass used for forming the 20VTG case, the neck O.D. may need to be turned to provide adequate clearance to fit the rifle's chamber. If forming cases from .223, the newly-formed neck on 20VTG is actually the walls from the case body, which is thicker and may also taper along its length (varying wall thickness along neck). Aside from potential thicker walls that need to be reduced for proper clearance, some shooters prefer more clearance than .002". Also, there are 20VTG reamers that are designed for "No Turn" that have neck O.D. of .235" or more.

If the newly-formed neck has irregularities then think of the this becomes a ping pong match.... run expander ball or mandrel through neck to create a uniform neck I.D. This process pushes the defects to the exterior of the neck. Upon firing the loaded cartridge, the case expands to chamber and as the neck makes contact with the chamber the exterior irregularities now get pushed back to the inside of the neck... repeat process. Even if the newly-formed 20VTG cases have adequate clearance for the rifle's chamber, it is a common practice to do a light skim cut (light neck turn) to remove any major irregularities (knock down the peaks) and create a more uniform wall thickness down the length of the newly-formed neck. Depending upon the rifle and intended use (type of shooting and level of precision required), these additional steps may/may not be meaningful to the shooter.

Lapua brass has thicker case walls (premium brass case) then some other manufacturer's cases. A few years ago a group of 300BO shooters compiles a list of brass cases to be used for converting into 300BO. The list included case wall thickness by manufacturer (some even by production year). It might be a good starting point for identifying potential brass for your "backwards engineering". I'm not sure if this list has been updated. Do an internet search and you'll find it. Just keep in mind that it may not be an exact comparison since the 20VTG's neck is formed from a different portion of the .223/5.56 case then portion of case used for the 300BO's neck.

Good Luck

 

[mefizto]

Hi Oso,

thank you again fro your time sharing your "novice" experience with a "pre-novice".

I understand the issues with chambers dimensions, hence my backwards approach. I have been very concerned, that the 20VT being a wildcat may not have a support by case manufacturers, to wit Lapua, hence my foray to the case reforming.

It was, in fact the very notion, both on the different fora's discussion and the actual measurements, that Lapua's cases are thicker that made me think about reforming the .223 cases. Since, as you noted, the neck is formed from the thicker body, I speculated that this might give me the neck size similar to the original Lapua cases. Which the current measurements support.

Thus, if I were to specify a "no turn" reamer for the Lapua cases, I will solve two issues (1) I can use the .221FB Lapua cases that I have, and (2) the chamber would work for the re-formed cases. Hence my question, how much clearance for the chamber is required. With that, I will now search for the "no turn" reamer for Lapua cases.

Regarding the proposed "ping-pong match", I wonder if this could not be solved by instead of using a bushing die use a collet die, which forms the outside diameter about a mandrel inserted inside the case. However, there does not seem to be one made for 20VT.

Thank you for the suggestion re the list of case wall thicknesses.

Kindest regards,

M

 

[Oso]

Reach out to the guys on Saubier. They can point you in the direction of a No Turn Reamer designed for use with cases formed from Lapua .223 cases.

 

[L.Sherm]

Are you wanting a reamer design for a no turn 20VT using Lapua 221 fireball cases or Reformed Lapua 223 cases to 20VT

 

[mefizto]

Hi Oso,

I do have an account on Saubier, but cannot recall the password and although I tried to reset it several times, I never received the password reset link. I had a difficult time to register in the first place, I had to contact a moderator. I will contact the moderator again.

Just to correct your reply, I am reforming several non-Lapua .223 cases. I am using the Lapua .221FB case as a reference.

Hi L.Sherm,

ideally both. As you can see from the measurement, the neck wall thickness is the same for the Lapua .221FB cases and the reformed non-Lapua .221FB cases, the only difference being the outer diameter of the reformed case, due to the Redding .221FB die. So, I am hoping that when I acquire a Redding VT bushing die and a bushing with the "correct" diameter as per Oso's advice, both will resize to the same neck size.

Do you think that I am missing something?

Kindest regards,

M

 

[L.Sherm]

If it was me running Lapua brass I would have the .200 line .2765, .235 neck and freebore 0 no matter the brass.
Remington, LC ect. .274 .200 line .232-.233 neck and 0 freebore

 

[mefizto]

Hi 457ciSBC,

first, thank you for your generosity providing the print. Reviewing it, is the .20 VarTarg shoulder angle not 30 deg, instead of the 23 deg as in the print?

Hi L.Sherm,

considering that I am pre-novice, can you please explain the reasoning for the different dimensions for the neck of the Lapua and the non_Lapua cases? Per my measurement, the wall thickness is the same for the Lapua .221FB cases and the re-formed non-Lapua cases; the difference in the outer diameter baind due to the Redding full body die. Thus, both should form to the same dimensions by the bushing die, no? Why then the different neck dimensions?

Second, is the diameter at the .200 line that you cite correct? The reamer posted by 457ciSBC reads at the .200 line 0.3769, and, as best as I can measure the diameter of the Lapua cases at the .200 line it reads 0.375; the re-formed non-Lapua cases 0.373-0.374.

Provided that the neck in both the lapua and the non-Lapua cases can be formed to the same dimensions, as I speculate based on the measurements, is it then the 0.001 to 0.002 inch difference at the .200 line, will necessitte select between the Lapua and the non-Lapua cases?

Sorry for all the questions, but I need to understand all the issues.

Kindest regards,

M

 

[L.Sherm]

Neck difference is because necked down Lapua 221 fireball will be .231-.232 loaded round.
Rem will be about .228 loaded.
Run a Lapua case through your sizing die and see were the case ends up about .274 then I would shoot for .2765 if its bigger then .2769. Depends on the sizing die used.

 

[457ciSBC]

Hi 457ciSBC,

first, thank you for your generosity providing the print. Reviewing it, is the .20 VarTarg shoulder angle not 30 deg, instead of the 23 deg as in the print?

Hi L.Sherm,

considering that I am pre-novice, can you please explain the reasoning for the different dimensions for the neck of the Lapua and the non_Lapua cases? Per my measurement, the wall thickness is the same for the Lapua .221FB cases and the re-formed non-Lapua cases; the difference in the outer diameter baind due to the Redding full body die. Thus, both should form to the same dimensions by the bushing die, no? Why then the different neck dimensions?

Second, is the diameter at the .200 line that you cite correct? The reamer posted by 457ciSBC reads at the .200 line 0.3769, and, as best as I can measure the diameter of the Lapua cases at the .200 line it reads 0.375; the re-formed non-Lapua cases 0.373-0.374.

Provided that the neck in both the lapua and the non-Lapua cases can be formed to the same dimensions, as I speculate based on the measurements, is it then the 0.001 to 0.002 inch difference at the .200 line, will necessitte select between the Lapua and the non-Lapua cases?

Sorry for all the questions, but I need to understand all the issues.

Kindest regards,

M

Yes you right sorry, it should be 30 degree…good catch. I modified my 20-222 print and missed that.I will make the change and repost.

 

[457ciSBC]

Yes you right sorry, it should be 30 degree…good catch. I modified my 20-222 print and missed that.I will make the change and repost.

 

[mefizto]

Hi L.Sherm,

thank you for your patience answering, but I still cannot reconcile your assertion with the measurements. If the Lapua .221FB case's neck outer diameter is .248" and the non-Lapua re-formed 221FB case's neck outer diameter is 0.254", which BTW is exactly the inside diameter of the .221FB die, I do not understand how they end with .231-.232" diameter respective .228" when loaded.

Please do not misunderstand, I am not doubting your experience, it just does not make sense to me based on the measured dimensions. I really need to save some money for the bushing die and some .20 bullets and finishing loading the cases.

Regarding the disputed dimension at the .200 line, here is a picture of .221FB: https://www.google.com/url?sa=i&url...ved=0CAoQjRxqFwoTCKDa5dWjn_ECFQAAAAAdAAAAABAD.

Hi 457ciSBC,

thank you vary much.

Kindest regards,

M

 

[L.Sherm]

I am not sure on the reformed 223 Lapua brass ive never reformed 223 Lapua brass only LC brass. My suggestion is if you reform any 223 brass to 20VT get the tools to neck turn no matter what brand or reamer.
Or just stick with some kind of 221 fireball brass.

 

[L.Sherm]

You cannot measure a Lapua 223 case neck and compare it to a 221 fireball neck the 223 case body will become part of the reformed neck to 20VT

 

[mefizto]

Hi L.Sherm,

I am not sure why the language "reformed 223 Lapua brass" keeps creeping from, I had already at least twice specifically wrote that I am not re-forming 223 Lapua brass.

I am not measuring "Lapua 223 case neck and compare it to a 221 fireball neck", but rather measuring the neck of the already re-formed .223 case, in other words the neck that has been formed from the .223 case body.

Since it does not appear that we can understand one another, I will abstain from any further discussion until I have build the rounds from both the .221FB Lapua case and the re-formed .223 non-Lapua cases.

Kindest regards,

M

 

[Oso]

Hi L.Sherm,

thank you for your patience answering, but I still cannot reconcile your assertion with the measurements. If the Lapua .221FB case's neck outer diameter is .248" and the non-Lapua re-formed 221FB case's neck outer diameter is 0.254", which BTW is exactly the inside diameter of the .221FB die, I do not understand how they end with .231-.232" diameter respective .228" when loaded.


M

Regardless of the Neck O.D. (.252" - .254") of either a 221FB case or 223 case (both .224 caliber), the neck on both cases will be reduced (shrunk) in order to form a 20VTG case that fits a .204 diameter bullet... not .224 diameter bullet... this is where/how we arrive at the .231" - .232" O.D. As part of this reduction process the thickness of the neck's case walls increase as we collapse the I.D down from .224 to .204, resulting in either (1) the need to neck turn the 20VTG formed cases or (2) rifle to have an over-sized chamber to accommodate thicker necked cases ("No Turn").

Depending upon the cartridge type of the donor case (221, 222, or 223) as well as the specific manufacturer of the case, the dimensions of the donor brass will vary and ultimately affect the dimensions of the 20VTG case. I mention this because you are going to be measuring case necks of 20VTG cases that were already formed from 223 cases. Keep in mind that these measurements will change when you want/need more 20VTG cases, because the donor case will vary even if it is from the same manufacturer. The only way around this is IF you are buying pre-formed cases that are being trued/trimmed/and neck turned as part of services provided by the custom case seller/maker. These custom made cases can get expensive, but cost may be acceptable depending upon the quantity (# of cases) that you want on hand. Despite all the best planning, there is a good chance that you will need to do some neck turning to feed this rifle... just keep that in the back of your mind.

If it is an established cartridge that is widely accepted then all of the major reamer manufacturers and die manufacturers in the US will have established designs on file. There are thousands of 20VTG shooters who have been using the cartridge for over a decade, who have tried and tested all aspects of the cartridge. What I have learned in my brief time in wildcat is "Don't Recreate the Wheel".... someone else has already tried or thought about whatever you're questioning/exploring. Unfortunately, most of these experienced hands in wildcatting are older and less likely to have felt the need to do a write-up and spontaneously post their experiments and findings on the internet. You just need to ask the question and wait to get the response from those who have the knowledge... thi time of year they may be out hunting/shooting prairie dogs, ground squirrels, wood chucks, and all of these other mysterious free-ranging targets that we only get to read about. Its hard to be patient when you are focused and excited on a project that you can wait to start using.

Side Note: Sherm helped me build a couple of wildcats, including converting a vintage Sako into a 20VTG. I was hoping he would join in on this thread to lend his knowledge and practical experience building rifles. He was extremely patient and kind with me when I was trying to figure everything out for the first time. I have no doubt that I was a perplexed as you are when I started my project 4 years ago.