224 Valkyrie New AR-15parts.com 24" Bull Barrel AR15 Upper load issue

[Linko]

Hi, I wanted another project and I purchased a nice new 224 Valkyrie upper for my S&W ar-15. To go along with my 223 and 300 blk uppers.

I loaded up some Berger 80.5 bullets in starlite brass, cci 400 primers with CFE223 26.2 26.4 & 26.6 grains 2.260 COAL and off to the range.

Geeze every round failed to cycle the bolt and took major effort to remove the spent brass. accuracy was poor at 100yds (3").

never had this kind of issue loading for an AR before.

Could the coal be too long for this bullet and its causing an over pressure by touching the lands? Appreciate any advice.

Or should I be getting a small base die? I am using a Whidden FL Bushing die.

I am triple checking my cases and process before I try again.

thanks

 

[fkimble@charter.net]

Will a live round chamber OK and then extract OK by hand? May want to double check that the gas block hole is lined up with the barrel gas hole. Do they try to extract? Will a fired round go back in the chamber and lockup OK? Will a resized case chamber OK? No experience with CFE223 powder. I'd double check every thing gas related in that new upper. Any chance you have any factory ammo for it? If so does it work. Apparently new brass chambers OK? Some more info please!

Frank

 

[TAJ45]

^^^^ Nice solid list of things to check.

 

[jelenko]

Could the coal be too long for this bullet and its causing an over pressure by touching the lands?

Unless the chamber wasn't cut right, 2.260 is just mag length => should be completely fine.

 

[Linko]

Will a live round chamber OK and then extract OK by hand? May want to double check that the gas block hole is lined up with the barrel gas hole. Do they try to extract? Will a fired round go back in the chamber and lockup OK? Will a resized case chamber OK? No experience with CFE223 powder. I'd double check every thing gas related in that new upper. Any chance you have any factory ammo for it? If so does it work. Apparently new brass chambers OK? Some more info please!

Frank

thanks for the things to check.

I will start getting answers to these questions.

1. A fired case will chamber but not extract using the charging handle without great effort. ( hitting the handle with a nylon mallet)

2. A resized case will chamber and extracts with the charging handle, (a little tight).

3. A resized case and bullet loaded to 2.260 coal chambers and extracts ok. (no powder/primer) This coal is Not touching the lands, checked with grease pencil.

4. Pulled the gas block and verified it is correctly aligned with port

5. Neck sizing. The problem loads were neck sized with a .248 bushing (Whidden FL Bushing die)
here is my math:
.224 bullet
+.030 neck thickness (.015 x 2 using a ball mic)
__________
= .254
- .003 (.002 + .001 spring back)
___________
bushing S/B .251
bushing used .248
______
excess .003

Is this neck too tight, that its causing an over pressure?

 

[fkimble@charter.net]

If I understand correctly, the problem loads were neck sized? Does this mean other loads full length sized worked OK? An AR is not a weapon I would use a necksizer on. It needs to be full length sized to insure the .200 area of the case is resized enough to freely chamber and eject. Also sounds like your neck sizing is way to tight. Using such a tight bushing may also cause the neck to force the body/shoulder junction to expand outward causing a tight or even no go situation. Same as when a seating die body is screwed down too much and is hitting the end of the case swelling the body/shoulder junction.
So please verify, are full length sized brass loads working? Also some fast powders do not produce enough gas to correctly operate an AR's gas system. I know Accurate 2220 is one of those. Did you by chance measure the diameter of the gas port?

Frank

 

[Liven The Dream]

Trim length of Brass -.003 ? or +.006 ?

Shoulder set Back enough

Small Donut at base on Neck U Bushing Dies do those things )

 

[mudduck]

Gas tube long enough? Friend just had this problem and had tube was to short

 

[Linko]

If I understand correctly, the problem loads were neck sized? Does this mean other loads full length sized worked OK? An AR is not a weapon I would use a necksizer on. It needs to be full length sized to insure the .200 area of the case is resized enough to freely chamber and eject. Also sounds like your neck sizing is way to tight. Using such a tight bushing may also cause the neck to force the body/shoulder junction to expand outward causing a tight or even no go situation. Same as when a seating die body is screwed down too much and is hitting the end of the case swelling the body/shoulder junction.
So please verify, are full length sized brass loads working? Also some fast powders do not produce enough gas to correctly operate an AR's gas system. I know Accurate 2220 is one of those. Did you by chance measure the diameter of the gas port?

Frank

Hi Frank,

Thanks again for your insight.

All of the initial loads were a problem (jammed not extracting w/o force) and were FL sized with a Full Length / Bushing die.

I only have been to the range to test fire once so far.

My Load using CFE223 was as close to the Hornady load data for an 80 grain Sierra HPBT as I could get.
I used Berger 80.5 bullets
Hornady CFE 223 range = 24.3 to 26.6 - (I loaded 26.2 26.4 26.6)
Since I first loaded this bullet with CFE223 I read about a successful load using these Bergers with much less power (25.6 grains) (224 Valkyrie forum) Maybe I am too hot. I Don't see primer issues though. I think I lowering the charge level a full grain is going to be included in my next outing at the range. (25.2 25.4 & 25.6)
Coal 2.260
GM205M primers - I used Rem 6 1/5 , I will try some GM205M primers next trip to the range
Sized Trim length looks +.003

 

[fkimble@charter.net]

OK, thanks for the additional info. Sounds like you may have just started a little too high on your first loadings. Be careful with those Rem 6 1/2 primers, they are designed for 22 Hornet pressure cartridges, not high pressure stuff. 7 1/2 are their higher pressure primer. CCI 400 are a middle pressure primer. I have loaded workups with CCI 400's til they flattened out noticeably, then switched only the primer to CCI450 and there was absolutely no flattening. Can't see where your different primers would cause much if any pressure differences though. Hard to believe over pressure in an AR would not eject at all. Usually over pressure just yanks them out bending the rim or ripping a chunk out of the rim. Puzzling. Let us know how the next range trip goes. If possible, how about showing us a pic of a fired case head with a good in focus closeup, and a side view next to an unfired case.

Frank

 

[Linko]

3 fired on the left. new is right one

 

[Linko]

next load plan:

GM205M primers
CFE 223 25.2 25.4 25.6 grains
new larger neck bushing .251
check trim length after FL sizing

 

[fkimble@charter.net]

Another thought, the Starline brass may be thicker with less internal volume than the Hornady brass. This could cause higher pressure than the Hornady brass and also unfired brass usually has less volume than fired brass, especially neck sized brass. Keep us posted on your next range trip.

Frank

 

[Linko]

yes good point. I found I needed larger neck bushings for the Valkyrie than my Lapua 223 brass.

 

[garandman]

I got a 224 Valkyrie in a bolt gun and both the 80.5 Berger and 85.5 Berger like to be loaded long..... 2.30+" That's obviously too long for AR mags. Both shoot 0.3 - 0.4" at 100 yd. in my gun.

 

[NZ_Fclass]

Back in the day, before our left govt stole my AR....

I had a similar issue with a 223 build, which was found to be the position of the gas key on the bolt carrier. A few mm adjustment fixed it.

 

[searcher]

There are a few problems which prompt about 95% of cycling problems (failure to cycle). The bolt MUST be pushed rearward enough to allow a round to be stripped off the magazine. If after firing the first round - another round is not being picked up off the magazine - you are not getting enough "gas" to propel the bolt to the full rearward position - which it must do in order to snap back and pick up another round off the magazine. Here is what to do as a process of elimination. 1)If using a new, unfired bolt assembly, the sharp edges on the new gas rings on the bolt can provide just enough resistance to prevent the bolt from freely sliding in and out of the bolt carrier so as to prevent the bolt from reaching the rearward position after being fired. Pull the bolt carrier group out of the rifle. Disassemble bolt from carrier. De-grease and remove all tracers of oil with brake cleaner or similar. Rapidly work bolt in and out of bolt carrier in short strokes about 200 times. This takes about three minutes. Re-lube and reassemble. This is VERY common occurrence until a rifle is "broken in". 2) Verify the gas block is aligned vertically and pushed to the rear of the rifle until it stops on the machined shoulder on the barrel (if can be loosened by Allen screws). 3) Verify that the powder charge being used is at least 3/4 of the way up from starting load to max load as shown in the manual. This is more typical using light bullets but can also occur with very light powder charges. If the bullet IS stripping off the magazine after the first shot is fired - but the bolt is not locking up on the chambering round - then one would do well to break in the gas rings as described (assuming new bolt), then determine if the headspace of the resized brass might be too long (compare with unfired factory brass using a Hornady tool if you are not sure) or your bullet is seated too long - as it may be running into the lands when the round is chambered. It almost always comes down to either not enough gas or sizing too "long" or bullet seating "long". good luck! And get rid of those 6 1/2 primers......

 

[Linko]

Today was the second range visit.

After firing a round the bolt doesn't budge rearward at all.

Fires fine and the case doesn't stick in the chamber now with 1 grain less power in this (2nd) load

New Brass, GM205M, CFE223 25.2 grains. Checked loaded Base to shoulder before and after firing. about .003 difference. I marked the seated bullet on a (no powder) round with a marker on one side and a grease pencil on the other to see if its touching the lands, it isn't.

Dissembled the BCG and cleaned the BCG. The rings do see sharp. Will try the method searcher suggested to break in the rings. Checked gas port alignment, looks aligned. (Pulled it off and checked position of port). What size in the barrel should the port be?

 

[mike mccormick]

Check alignment of your gas port with a borescope.

 

[Linko]

Check alignment of your gas port with a borescope.

will do