Loose primer pockets on Starline

[Juggerxxx]

I purchased 150 pieces of large primer Starline brass for the first time. It’s for an AR10 chambered in 6.5CM. I believe I am on my 4th or 5th firing and 50% of them have loose primer pockets to the point of almost no resistance when seating the primer. 4 of them would even have the primer fall out when tapping the brass on the table. I can typically get 12-13 firings from Hornady brass. The failure point with the Hornady brass is not the primer pockets rather it’s case head separations. The Hornady brass is not fired from the same gun and is fired from a bolt gun. The Hornady brass is loaded with 42.2gr of H4350 and 140ELD. The Starline brass is loaded with 42.0gr of H4350 and 140ELD.

Anyone else had primer pocket issues with Starline brass or is it just me? Is this something to do with being fired from a gas gun?

 

[FCS]

Absolutely has to do with being fired from a gas gun. Starline has generally been pretty darn good stuff in my experience. If you are loosing primer pockets at 4-5 loadings, that is a little early but gas guns are not bolt guns.
Starline has a noticeably different (less) case capacity than does Hornady, if you are running 0.2 gr lighter charge in the Starline you are running more pressure then in the Hornady brass.
Heavy up buffer or choke off gas to keep bolt locked up a little longer. Obviously you need a gas gun to cycle 100% reliably so you can't get to crazy on buffer weight and choking down gas; 100% reliable cycle, lock back on an empty mag but really no more gas then that.

How long is barrel?
What length is gas system?
Buffer weight?

 

[918v]

You can’t run a max load developed for a light weight case in a heavy case.

 

[EnjoyTheWilderness]

SRP or LRP? I think Starline offers both in 6.5CM.

(Edit... I just noticed you mentioned it was large primer. Is this an example of why some like SRP vs LRP? I am currently doing load development for similar gas gun, but I am using Peterson SRP brass. I noticed pressure issues as I was approaching max load with the same powder and same bullet, so I am looking to load a bit less than max. I was also having issue with the gun being over gassed and being pretty hard on the brass.)

 

[Juggerxxx]

Absolutely has to do with being fired from a gas gun. Starline has generally been pretty darn good stuff in my experience. If you are loosing primer pockets at 4-5 loadings, that is a little early but gas guns are not bolt guns.
Starline has a noticeably different (less) case capacity than does Hornady, if you are running 0.2 gr lighter charge in the Starline you are running more pressure then in the Hornady brass.
Heavy up buffer or choke off gas to keep bolt locked up a little longer. Obviously you need a gas gun to cycle 100% reliably so you can't get to crazy on buffer weight and choking down gas; 100% reliable cycle, lock back on an empty mag but really no more gas then that.

How long is barrel?
What length is gas system?
Buffer weight?

It’s a 20” barrel from PSA and I’m not sure of the gas tube length and buffer.

I did perform an OCW with the Starline brass but did not see and do not currently see an pressure signs. I do get what your saying about comparing case volume and the pressure being different. I’m going to fill each up with water tonight and weigh them but the wall thickness seemed fairly similar and even used the same setting when neck turning.

 

[Mtkrusmark]

I get about 6 reloads out of my LRP .308 starline brass and then have to throw them because of the primer pockets being super loose. I have made starline aware of this and they said they would look into it and I told them I would send them my brass if they wanted to look at them. I shoot a dpms LR308 gas gun

 

[padom]

So your saying you get 10-12 reloads in a 6.5cm bolt gun with Hornady but only 5-6 reloads in starline in a gasser??? Doesnt compare, different animal.

Also, 41.8gr H4350 in Hornady brass with 140 eld has been my go to for years in my 22" 6.5cm Bartlein +2 gas.....so if your running 42g in starline which has less case capacity I would say 5-6 reloads is doing really good...

 

[Juggerxxx]

So your saying you get 10-12 reloads in a 6.5cm bolt gun with Hornady but only 5-6 reloads in starline in a gasser??? Doesnt compare, different animal.

Also, 41.8gr H4350 in Hornady brass with 140 eld has been my go to for years in my 22" 6.5cm Bartlein +2 gas.....so if your running 42g in starline which has less case capacity I would say 5-6 reloads is doing really good...

Do you or anyone else have quick loads that could compare case capacity between the Starline and Hornady? I can measure the water weight between the two and it would be nice to know an equivalent power charge for the Hornady brass that would produce the same pressure. I would like to take one new piece of Hornady brass and fire it every time I go to the range to see how the primer pockets hold up on in the AR10

 

[padom]

Do you or anyone else have quick loads that could compare case capacity between the Starline and Hornady? I can measure the water weight between the two and it would be nice to know an equivalent power charge for the Hornady brass that would produce the same pressure. I would like to take one new piece of Hornady brass and fire it every time I go to the range to see how the primer pockets hold up on in the AR10

I'm getting about 5-6 reloads out of the Hornady in my 6.5cm gasser with the 41.8gr load... start at 41gr and work up and watch velocity and pressure signs in the starline..

Hows your brass look? Hows the heads look? Primers flat? Heavy swipes?

 

[Juggerxxx]

I'm getting about 5-6 reloads out of the Hornady in my 6.5cm gasser with the 41.8gr load... start at 41gr and work up and watch velocity and pressure signs in the starline..

Hows your brass look? Hows the heads look? Primers flat? Heavy swipes?

What is the failing factor with your Hornady brass after 5-6 firings in your gas gun?

I did a full OCW with the Starline brass and only started to see slight pressure signs at 42.8-43.0gr.
With the 42.0gr I settled on I am seeing nice round corners on the primers and nothing nasty for ejector marks or swipes.

 

[padom]

What is the failing factor with your Hornady brass after 5-6 firings in your gas gun?

I did a full OCW with the Starline brass and only started to see slight pressure signs at 42.8-43.0gr.
With the 42.0gr I settled on I am seeing nice round corners on the primers and nothing nasty for ejector marks or swipes.

Geez that's hot...43g is my 123L load. 42.8g - 43g with a 140 is a very hot load for a gasser.. I think your right where you need to be and are getting what you should out of the brass.

Loose pockets is my failing factor

 

[Juggerxxx]

So I measured the case weight volume of the Starline and Hornady brass. The biggest difference was 2.0gr or ~2.5 drops of water difference. I have no idea how much this translates to pressure with the same powder charge but that doesn’t seem like much from an ignorant individual such as myself?
Not sure if this make a difference but
-I weighed 3 pieces of each
-each was trimmed to the same length and filled to the same level
-each case had been previously fired and not cleaned
-each case had a primer

Below are the actual weights.
Starline = 52.1, 52.3, 52.4
Hornady = 53.9, 53.9, 54.1

 

[918v]

In 308 2 grains water capacity translates to a 1.5gr powder charge reduction

 

[Juggerxxx]

In 308 2 grains water capacity translates to a 1.5gr powder charge reduction

Holyshit I never would have figured. I am curious if that is close with the 6.5CM, H4350 and 140ELD?

 

[FLIGHT762]

Your primer pockets are telling you your load is too hot, unless you're okay with toasting them in 4 reloads. Been there, done that. Drop your load down. Gas guns are not bolt guns.

 

[JOE62]

3.6% difference in water capacity = 1.5 grains of powder. If primer pockets are getting loose, there is pressure. Have you miked the case heads to see how much expansion you are getting?
My primers are flat with 41.5 gr of H4350 and 140's in my bolt gun with Starline LP brass.

 

[HeadHunter10]

3.6% difference in water capacity = 1.5 grains of powder. If primer pockets are getting loose, there is pressure. Have you miked the case heads to see how much expansion you are getting?
My primers are flat with 41.5 gr of H4350 and 140's in my bolt gun with Starline LP brass.

In 308 2 grains water capacity translates to a 1.5gr powder charge reduction

The Starline case has room for 1.5 gr less of powder but that doesn’t mean that you get the same pressure as if you actually used 1.5 gr more right? Are you saying that if I use 40.2 gr of RL16 in Starline brass with a 143 gr ELD-X it would be the same pressure as using 41.7 gr in Hornady brass?

 

[Danale147]

Agreed with the gas guns, they are brutal on brass. In my bolt I'm using 42.5gr H4350 with 130 ELD's and that is pushing hard. I've used nothing but Starline brass in my 6.5, and the last lot went 15 firings before i decided I would buy some new stuff. Primer pockets were not an issue. In my 6.5 gas guns I have has issues with the firing pin hole being sloppy and causing primer issues that way. Definitely back the load down a bit, but I wouldn't expect the brass to go a whole lot longer than what you are seeing now. Even if the pockets hold up, gassers are very hard on brass.

 

[918v]

The Starline case has room for 1.5 gr less of powder but that doesn’t mean that you get the same pressure as if you actually used 1.5 gr more right? Are you saying that if I use 40.2 gr of RL16 in Starline brass with a 143 gr ELD-X it would be the same pressure as using 41.7 gr in Hornady brass?

Pretty much yeah.

 

[Juggerxxx]

I am starting to see the truth you guys are stating. Remember this is my first large gas gun.
As I mentioned in my posted above; I have been testing Hornady and Prime(Norma) brass with the same charge weight and bullet as the Starline. It appears as of the last trip to range that the Hornady and prime brass is also experiencing loose primer pockets right around the same number of firings (5-6) as the Starline. I am aware all three of these have different volumes of case fill but it was still nice to see the similar results.
Now I would like to know or test small primer pockets to see if they are able to get more than 5-6 firings?