Planned .20 Practical Ammo Project

[fyrewall]

I have a .20 Practical; it is a Ruger M77 MKII, formerly a .223. I had it re-barreled with a 1-11 McGowen 24 inch about #2 contour. 4 LG beautiful inside.

I have a real good supply of new Lake City (American Eagle) 5.56X45, Lapua .223, and Nosler .223 brass. And about 2X as much fired and once fired stuff.

I have:

F/L .223 Redding bushing die with a .226 bushing and a Hornady .20 seat dies.
Lots of 40 gr. Hornady .204 VMax bullets.
3 bricks of CCI #41 primers.
a Magnetospeed Chrony will be on hand soon

My plans are to test loads using Alliant AR Comp, IMR 8208, and Ram-Shot TAC. Another powder that might be considered is H4895. I will test for accuracy @ 100, velocity spreads, accuracy at maximum ranges, most likely at 300 but hopefully at 550 yards. When I get a good idea of what the velocity spreads are for each powder using samples of 20 I will play around with some statistics to get some idea of what mean vel. spreads might be expected for samples of 500, 1000, & 1500 loaded rounds (Student's T, like from Stat 101). Allowing for the availability of 3-4 powders and 4 brass brands testing has to be limited and with different powder charges this could be real time and $ consuming and there is my beautiful McGowen barrel. I like all 4 powders and have used IMR 8208 in the past and will probably start with that. R-S TAC is another possibility as it can also be used in the .308 with 168 gr. bullets.

In my Berger manual there is some statistical stuff. Should you shoot at some 100's of rounds at rodents up to 500 yards what and how many bullet drops (trajectory) might be expected caused by velocity spreads.

 

[LitLBoy]

If you start with the 8208 you won't bother testing any other powder. PM me if you want exact data.
LitLBoy

 

[nmkid]

This is what my .20 P does with H-335 and 40 gr. Hornady's at 3750 fps. Magneto Sporter

 

[fyrewall]

Gaining ground with every look - thanks

 

[jepp2]

I have a .20 Practical; it is a Ruger M77 MKII, formerly a .223. I had it re-barreled with a 1-11 McGowen

What is your neck diameter? Mine are .233 and Lapua brass is pretty close. Loaded rounds measure .231"

I take my necks down in 3 steps. First I run them through a 223 die w/o the expander. This takes them down to .243". Next I run them through a Redding Comp bushing die with a .235" bushing. Last I run them through a CH4D FL die. The necks stay more uniform doing the 3 steps.

I shoot mostly 32 gr. and have used 2015 and H332 the last 2 years. But I tend to limit my shots to around 300 yards to keep my hit percentage high.

For once fired, I don't anneal before sizing down. 2X or more firings, I would anneal before sizing down.

 

[Recko555]

N-133 or 10X worked outstanding for me.

 

[fyrewall]

My bushing is .226, neck diameter of loaded rounds is .228, brass is trimmed to 1.76, COAL is 2.23, neck walls .012. This should be .012 + .204 + .012 = .228 with a neck tension of .002.

(1)My first step with new and once fired brass is to run .223 through a Redding small base body die (74111, some once fired brass sticks upon extraction, those AR rifles?, lube up brass)

(2)annealing once fired .223 brass

(3)Redding 77111, .223 Rem F/L bushing die with a .226 bushing and no expander but a decap pin held in place with a ground down .223 expander (this reduces the .223 brass down to .20 and F/L & neck sizes fired .20 P's ),

(4) neck turning just enough to clean up necks after running newly necked down brass over a .20 expander (a .20 expander is in a RCBS .223 F/L die adjusted not to contact shell holder) this step is skipped for brass that has been neck turned.

(5) final trimming

Lots of work but subsequent .20P loadings are much faster with only step (4). I shoot 40 grain H VMax bullets and the bullet boat-tail/body junction is seated just above the brass neck/body junction and this fortuitously also works well with the bullet rifling engagement thing. I use a generic .20 Hornady seat die, this works with all .204 bullets. Annealing after 4 cycles. .204 bullets easily slip fit inside fired brass.

Every time I shoot the .20P it amazes me and having a history of living with low scores I take shots out to 440 and more and have made hits out to 440 yards (misses also). I would like to get some idea of what velocity spreads might be expected for bulk loadings and the subsequent affects on trajectory out there. I have used IMR 8208 (gorgeous metallic gold color on container) and don't really see a reason to change except to have some other powder as a backup in the event of another component availability emergency. On some trips I have shot 250-275 rounds per day using the .20P & 2 other rifles. My batting average is 660 or so, except when the land owner, not interested in sport, wants me to remove lots of them then it is 200-250 yards and I bat 850 or so. Temps may range from 50F to over 90F - interest is IMR 8208, Alliant AR Comp, & possibly R-S TAC.

I use CCI 41 primers.

 

[GrocMax]

40 vmax + 7 1/2's + Benchmark. Benchmark is extremely close to 8208 in speed but I get better accuracy. Not finicky on powder use what 223 midweight bullet powder you have.

On fired or milsurp brass check trim length as necking down lengthens the case. If you start out with 223 brass at 1.750" its good for 3-4 firings before trim. I'm a fan of the two step initial necking operation, also with milsurp or once fired using a small body die first op, have to as my 20P reamer is of the PTG small base variety. With new brass you should be able to neck down in one op and go as they are already ~.243" (LC) and .373" base instead of a fired 223 .250"+ish.

For bolt guns x2 on the Hornady 20 cal universal neck or modified (cut collet bottom .075") 204 Lee collet die. The Hornady universal 20 seater works good. LC brass is a 226 or 227 bushing, Lapua and IMI a little bigger, some thicker stuff might need a 230.

Every 0 freebore chamber I've had likes the 40 vmax .010"-.020" off.

For a cheap alternative I run surplus WC844 under a 34g VNE at 4000+.

 

[hogpatrol]

Two cents here with the disclaimer YMMV. Been shooting this round for several years. I run one brand, Remington, out of an AR, 10 twist and a modified 700, 11 twist. No neck turning and use a two step process for necking down, Redding dies. I stay religious on trimming, use a WFT. I found using different brands of brass requires different bushing setups, i.e. more work, not going to happen for me but YMMV. Turning necks for my rifles isn't worth the time for the small improvement. Tried that also. No advantage found using any high dollar brass like Lapua. In my rifles, LC was not accurate. Others my have different opinions on it but I'll scrounge it at the ranges and save it for scrap. The best brass I've come across is IMI but it's hard to find. I tried all the aforementioned powders and settled on VV 133, cleaner than most thus good for the AR and high volume shooting. My best loads use BR4s. Never had any success with ANY Remington primer and I tried them all. Again YMMV.
My favorite bullet is the BIB 40s. Haven't found another bullet that shoots as accurately. Next in line are BKs, Vmax and Bergers.

 

[nmkid]

I also do my brass, (Lapua & Win.) in 3 steps. There is no rush for me as I'm retired. An interesting note...While in the act of gathering .20 P info I contacted a gentlemen that is regarded as the .20 guru. He bad mouthed the .20 P as worthless because of the shoulder angle and that it would not be accurate. Sure got me a thinking but, I was so smitten with the .20 P I went ahead with it. As you can see by my target it's more than accurate. I use Redding type S FL bushing die and a Wilson seating die, (arbor press). Tried several powders but, in the end it was H335.

 

[fyrewall]

Good thought on the .204 Lee Collet die, some time ago I trimmed off the bottom of a .260 Rem collet for 6.5X47 Lapua use and it worked fine; I also reduced the diameter of the decap pin for the smaller 6.5X47 L flash holes. The only problem I have run into is that some pieces of once fired .223 brass need small base resizing because they will stick in the chamber after firing to such an extent the extractor will rip off the cartridge rim - this is with normal pressures - no expanded primer pockets. The small base die fixed the problem.

After reading the above I will run my new brass through a .223 F/L die that has no expander that will provide somewhat of a multi step neck down process. The once fired stuff will continue to go though the small base body die.

I still am undecided to neck down brass in more than one step. Going from an inside neck diameter of .224 to .204 is not that big a step, like .020 or a radius of .010. Possibly, turning necks is excessive but when I do turn them I see variations of neck wall thickness of .001 - one side is turned bright the other untouched; this is with Winchester and Remington .223 brass.

I don't think a difference of 7 degrees less shoulder angle and a tiny bit more body taper is enough to condemn the .20 P over the less practical "tactical" version.

I will also look into Benchmark.

 

[SenderoMan]

Good information!
I have used H4198 with good results.

 

[fyrewall]

I should have included when I did the modification on the Lee .260 Collet Die to allow neck sizing of 6.5X47, as related to .204 R Lee Collet die modifications to be used for .20P, I also cut off about .25 inches from the bottom of the mandrel or whatever it is called so it would not contact the bottom of the case. This removed the decap pin requiring me to reduce to diameter of a standard size Lee decap pin used in the Lee decap die so it would work for the small flash hole Lapua cases. I did this by spinning the decap rod in my DeWalt cordless and grinding the pin down with my Dremel.

Details and attention to them count. Modification of a .204R Lee Collet Die to make it work in a .20P for neck sizing is an ingenious way to solve a problem for neck sizing .20P's.

 

[GrocMax]

On the Lee collet dies, for the 20P or 20Tac in the 204R die if you do need to shorten the mandrel just spot face the bottom of the cap large enough diameter and about .125 deep so the top of the mandrel can go into it then stop, works the same as shortening it. Try without 'shortening' the mandrel first it may work as is. I prefer to set it up so the collet stays out of the neck/shoulder junction (donut area) thus the shorter mat'l removal than the bolt face to neck/shoulder distance between 204R and 20P. Just trim the bottom of the collet till it sizes down the neck far enough for you, will be less than .100".

 

[fyrewall]

On the Lee collet dies, for the 20P or 20Tac in the 204R die if you do need to shorten the mandrel just spot face the bottom of the cap large enough diameter and about .125 deep so the top of the mandrel can go into it then stop, works the same as shortening it. Try without 'shortening' the mandrel first it may work as is. I prefer to set it up so the collet stays out of the neck/shoulder junction (donut area) thus the shorter mat'l removal than the bolt face to neck/shoulder distance between 204R and 20P. Just trim the bottom of the collet till it sizes down the neck far enough for you, will be less than .100".

This is one of those, "how come I did not think of that?" I think the standard Lee decap die is not recommended for over .22 and this would be a better solution for .20P. The cap appears to be easily worked aluminum.

 

[GrocMax]

Yeah the collet neck sizer die caps are soft aluminum and like 4 bucks, did a quick check at leeprecision.com looks like same P/N cap for most of the dies. P/N NS2579.