Issues with new 6.5x47

[paparickzi]

Hey guys,

I'm not new to reloading, but am new to 6.5x47, bushing dies, and this is my first custom gun I've had built (have bought several second hand precision guns and new factory rifles).

I've recently finished a build in 6.5x47 (Stiller, benchmark) and am trying to start load development. Was chambered no neck turn. Started by trying to find the lands, seated a round at 2.800 OAL and marked it up with a sharpie with intent to continue to pull/seat bullet longer and longer till marks show up on bullet.... (using 140 bergers)

Very first time I tried chambering the round, I felt some resistance when pushing the bolt forward. Bolt was tough to open (can't remember if I had to actually smack the bolt handle with my palm to get it to release or not, but happens half the time). Took the round out, marks on the bullet were obvious, measured OAL and it was 2.775. Subsequent attempts have it pushed anywhere between 2.760 and 2.775.

So my chambers shorter than what book says it should be. I've never had this before, but like I said I'm new to new custom rifles, so it's probably no big deal and I can develop a load fine if I know where the lands are.. (or is this an indication that something is wrong?)

My concern is the difficulty to (sometimes) pull the bolt. My brass prep is pretty spot on I think. Even seating the bullet very deep for an OAL of less than 2.760 to make sure the bullet doesn't hit the lands, half the time the round chambers an extracts smoothly with no issue, and the next it will bind up on extraction.... then run smoothly the next try.

I've prepped and seated a round and took photos of each step and uploaded them to link below. Any input you guys have that could help me sort this out would be appreciated.

https://imgur.com/a/C9tQ1

 

[EBaker]

Look up on Youtube.com finding the lands by wheeler accuracy. Its a great video.

 

[dkhunt14]

Looks to me like you are in the lands very hard. Maybe as much as .0025 or more. Possibly what I call jamb length. Which is as long as you can seat a bullet without it being pushed deeper in a case. The bolt opening hard is probably because you are in the lands that hard. I would find out what free bore the reamer had. If it is short, I would get it throated out so the pressure ring of the bullet is in front of the neck shoulder junction. That will keep it out the donut area and give you more powder capacity. Matt

 

[hogpatrol]

I viewed your photos. The purpose of measuring the overall length is solely for magazine fit. Other than that, it's a useless number and can vary with meplat shape and form. You need to check base to ogive measurement not COAL. The sharpie on a loaded round with varying neck tension is a tough way to find the lands. You can get a measurement to the lands with a Hornady seating depth tool but a more precise way is the stripped bolt method as shown in Alex's video. Even with that you need additional tools to check CBTO, and you can do that with Hornady tools, an ogive nut or other tools.
For comparison, my 6.5x47 freebore is .140 and a loaded round with 130 Berger VLDs to the ogive is 2.060. That puts the pressure ring close but not past the bottom of the neck. The 140s shouldn't be that much different.

 

[M995]

After looking at the pictures, step 1 would be a more accurate caliper, step 2 sharpie from shoulder/body junction to metplat / rechamber & check for marks.

 

[Hondo64d]

Hey guys,

I'm not new to reloading, but am new to 6.5x47, bushing dies, and this is my first custom gun I've had built (have bought several second hand precision guns and new factory rifles).

I've recently finished a build in 6.5x47 (Stiller, benchmark) and am trying to start load development. Was chambered no neck turn. Started by trying to find the lands, seated a round at 2.800 OAL and marked it up with a sharpie with intent to continue to pull/seat bullet longer and longer till marks show up on bullet.... (using 140 bergers)

Very first time I tried chambering the round, I felt some resistance when pushing the bolt forward. Bolt was tough to open (can't remember if I had to actually smack the bolt handle with my palm to get it to release or not, but happens half the time). Took the round out, marks on the bullet were obvious, measured OAL and it was 2.775. Subsequent attempts have it pushed anywhere between 2.760 and 2.775.

So my chambers shorter than what book says it should be. I've never had this before, but like I said I'm new to new custom rifles, so it's probably no big deal and I can develop a load fine if I know where the lands are.. (or is this an indication that something is wrong?)

My concern is the difficulty to (sometimes) pull the bolt. My brass prep is pretty spot on I think. Even seating the bullet very deep for an OAL of less than 2.760 to make sure the bullet doesn't hit the lands, half the time the round chambers an extracts smoothly with no issue, and the next it will bind up on extraction.... then run smoothly the next try.

I've prepped and seated a round and took photos of each step and uploaded them to link below. Any input you guys have that could help me sort this out would be appreciated.

https://imgur.com/a/C9tQ1

Also possible your headspace is a little tight. Any clambering or extraction issues with empty brass?

John

 

[Drop Port]

I would start with the reamer print. With no issues other than FB it appears you are only running + or - approximately a .100" FB
My current batch of 140 Hybrids are 2.850" touching in a .198" FB chamber.

 

[paparickzi]

Look up on Youtube.com finding the lands by wheeler accuracy. Its a great video.

Thanks for that, that is a great video. Previously I've just used the hornady oal gauge, and it's always been accurate enough for what I've been doing... but lack of modified brass in 6.5x47 has me trying a new way... this is awesome. Can see the oal gauge being shelved for good.

 

[paparickzi]

I viewed your photos. The purpose of measuring the overall length is solely for magazine fit. Other than that, it's a useless number and can vary with meplat shape and form. You need to check base to ogive measurement not COAL. The sharpie on a loaded round with varying neck tension is a tough way to find the lands. You can get a measurement to the lands with a Hornady seating depth tool but a more precise way is the stripped bolt method as shown in Alex's video. Even with that you need additional tools to check CBTO, and you can do that with Hornady tools, an ogive nut or other tools.
For comparison, my 6.5x47 freebore is .140 and a loaded round with 130 Berger VLDs to the ogive is 2.060. That puts the pressure ring close but not past the bottom of the neck. The 140s shouldn't be that much different.

Thanks for the response. I do have the hornady comparator tools and do measure cbto when loading rounds. The only reason I had measured the oal is to get a starting point to make the original cbto measurement from. I guess my surprise came when the book oal was actually longer than my chamber. In all previous rifles I've loaded for, I've always started at book oal, then started seating bullets *further out* until I found lands or reached max mag length (usually mag length is limiting factor)

I'll have to ask a really newbie question here... how do you measure and know where the pressure ring is in relation to the neck? I guess my hesitation so far has been not knowing how short is too short for a loaded round.

 

[mikegaiz]

Your loaded round neck is .290, what is your chamber diameter? If it is smaller than .294 that could cause problems. You really need to find your bullet touching seating depth and work out from there. I have tried many bullets in 6.5/47 L and none have shot well touching, Don't worry about OLA unless you meplet trim. Fitting in magazine will not help your accuracy/ load development. If you want to feed from mag, you will not get accurate unless you have a very short chamber.

 

[paparickzi]

Also possible your headspace is a little tight. Any clambering or extraction issues with empty brass?

John

I'm not sure. I'll give it a try tonight. That was my bigger concern, as bullets I've had seated deeper than what they were being pushed back (thought the bullet was free of the lands) was still having issues with extraction. I'll try just some brass and see how it goes.

 

[paparickzi]

Your loaded round neck is .290, what is your chamber diameter? If it is smaller than .294 that could cause problems. You really need to find your bullet touching seating depth and work out from there. I have tried many bullets in 6.5/47 L and none have shot well touching, Don't worry about OLA unless you meplet trim. Fitting in magazine will not help your accuracy/ load development. If you want to feed from mag, you will not get accurate unless you have a very short chamber.

I'm not sure. I've asked the smith for the reamer print but he doesn't have it. I've been told it was a no neck turn reamer and several rifles have been chambered using it have had no issues from being too tight in the neck.

 

[dkhunt14]

The neck size is on the reamer. The gunsmith has to know what size it is. If my gunsmith didn't know the Freebore and neck size I would be hunting a new gunsmith. Matt

 

[hogpatrol]

My no turn chamber neck is .294.

Thanks for the response. I do have the hornady comparator tools and do measure cbto when loading rounds. The only reason I had measured the oal is to get a starting point to make the original cbto measurement from. I guess my surprise came when the book oal was actually longer than my chamber. In all previous rifles I've loaded for, I've always started at book oal, then started seating bullets *further out* until I found lands or reached max mag length (usually mag length is limiting factor)

I'll have to ask a really newbie question here... how do you measure and know where the pressure ring is in relation to the neck? I guess my hesitation so far has been not knowing how short is too short for a loaded round.

The pressure ring is where the bearing surface meets the base or boattail. For a more in depth discussion:

www.bergerbullets.com/wp-content/uploads/2013/03/COAL.pdf

 

[pat fulghum]

Have you found your lands measurement by ....

https://www.wheeleraccuracy.com/#!information/p62ad

or review
http://forum.accurateshooter.com/threads/finding-your-lands-video.3892411/


Double and Triple thumbs up on the "you must know the neck size of the chamber"

 

[curtis.hopkins]

May be worthwhile doing a a Cerrosafe chamber casting. I found this to be a worthwhile asset for the reloading toolbox.

 

[paparickzi]

Thanks for all the tips guys, definitely helped in sorting this out.

Seems like it was a combination of things causing the issue. First, upon watching my calipers closely and measuring the same item repeatedly, I was getting different measurements of up to 2 thou variance. They've since been replaced with some Mitutoyo's (what a night and day difference in feel and repeatability).

Smith has confirmed the neck is .293, which if everything is absolutely perfect should be no-neck turn, which it wasn't. Rounds that were being difficult to extract without being neck turned were all found to have some runout to the tune of 1-2 thou.... .291-.292 loaded rounds + 1-2 thou of runout in a .293 chamber doesn't work well.

Headspace did not appear to be a factor. Brass that had been neck turned down with the exact same measurement to datum as non-turned brass functioned without issue.

While the CBTO was not the issue (beyond knowing it was much shorter than book OAL), the Wheeler Accuracy technique in finding lands is AWESOME. Can't believe I wasn't doing this before, won't be using the OAL gauge for anything important from now on. Can't provide CBTO numbers right now (my comparator insert is at the post office ready for pickup today), but it appears being about .001 from the lands the pressure ring is still in the neck.

I've got one of the K&M expanding mandrels (and neck turners kits) on the way to clean up the neck prior to running them through the bushing die, and suspect that will address the issue of any 1-2 thou runout that seems to be the culprit.

Worst case scenario, there's some cerrosafe on the way as well just in case something still doesn't make sense.

Again, thanks for all the input guys. It definitely helped me work through this and learn some things I didn't know I needed to learn.

Cheers!

 

[Desert Fox]

I run into same problem when I first got my 6.5-47. Mine was pressure issue, I was not close to maxed load with H-4350 but I'm getting pressure sign on the brass. Its a head scratcher since some brass doesn't show extractor mark but other does. All the same load. I found out that my chamber neck diameter is .292 and my loaded round measured around .291 and sometimes .293. I neck turned all my brass to .0125. My loaded round now measures .290. That took care of the intermittent pressure spikes.

 

[Steveb]

Bruno's carries the Lapua case modified for the Hornady tool. it is not a stock part from Hornady though or it wasn't when I bought mine.

 

[Jarhead6870]

I have a couple of 6.5 Lapuas that were "short" when compared to book specs. If you are shooting the 140 Hybrids, most guys I know are jumping them from the start of load development at .020 if they can. This depends on the boat tail/shoulder neck junction. I started mine at .005 jump and had good results. The Hybrids are jumpers. My throat grew .035 after 1300 rounds and while velocity dropped, accuracy was still impressive and as good as it was with the original .005 jump. I've also heard of a few shooters jumping .050 and still having good accuracy.