Alpha 6bra brass problem

[madmixerman]

Anyone experiencing heavy bolt lift using Alpha brass? 268 neck dia. Loaded round .264, load is 30.6 gr. H4895, Fed. 205m primers and 105 Bergers.Fired brass is tight if put back in chamber, sized brass no problem. Had no problems when I used Lapua brass. Was up to 31.1 gr.in load development using Lapua with no issues. Guess might have to buy more Lapua brass.

 

[RegionRat]

Fired brass is tight if put back in chamber, sized brass no problem.

Have you tried to cycle your sized 1X brass yet?

How would you characterize your chamber and dies? Does the virgin Alpha seem to match your fireformed Lapua at the 200 line?

 

[Wheres-Waldo]

I wouldn’t call this a problem. From 6XC, 6Creedmoor and 6BR, with Lapua, Peterson and Norma, I’ve found this to be common, especially with higher pressure loads in several different actions.

Ive always just sized and pushed the shoulder back and it’s good to go.

 

[Jason Boersma]

Call alpha and talk with them about this

 

[madmixerman]

Have you tried to cycle your sized 1X brass yet?

How would you characterize your chamber and dies? Does the virgin Alpha seem to match your fireformed Lapua at the 200 line?

All Alpha brass has been fired,no virgin. Chamber was done by well known gunsmith. Dies were matched to fired Lapua brass by Harrels.

 

[Della]

Loaded round .264, load is 30.6 gr. H4895

When I switched from Lapua to Alpha I had to back off considerably. 30.6 was too hot. Heavy bolt lift above 30.4.

I’m at 3000 fps in a 28” MullerWorks barrel with 30.0 H4895. Wheeler #1 no neck turn reamer.

(edit: OCD brass)

 

[madmixerman]

When I switched from Lapua to Alpha I had to back off considerably. 30.6 was too hot. Heavy bolt lift above 30.4.

I’m at 3000 fps in a 28” MullerWorks barrel with 30.0 H4895. Wheeler #1 no neck turn reamer.

Ok, I'll back off some and see if that's the solution.

 

[Rset]

Has the brass been fired in a different chamber, or only in this one?

 

[madmixerman]

Has the brass been fired in a different chamber, or only in this one?

Only this one.

 

[GlennK]

Alpha brass has less capacity, so you will be reaching pressure sooner. As others have said take some powder out. Just out of curiosity what did 30.6 yield for velocity? I am betting it is cranking.....
Also is this ocd brass?

 

[madmixerman]

Alpha brass has less capacity, so you will be reaching pressure sooner. As others have said take some powder out. Just out of curiosity what did 30.6 yield for velocity? I am betting it is cranking.....
Also is this ocd brass?

2983, twice fired brass

 

[Della]

2983, twice fired brass

26“ barrel?

 

[madmixerman]

28

 

[GlennK]

Slower than I would have thought. Interesting

 

[RegionRat]

I guess by now you got the concept that a load work-up should be run when there is a difference in case volume. That should end your problems, but since this is a learning exercise...

Would you say that the clicker brass shows sings of pressure? Ejector imprint or primer flow?

What is the 200 line diameter on your fired Lapua compared to your clickers?

Any idea of the internal volume difference between your cases?

These are the things to take away as the experience and price paid for your lessons. Sometimes they are black and white, and sometimes they are a little vague. But, as you gain experience both good and bad, it helps to learn faster by not passing up learning opportunities of your own rather than just rely on those of others.

 

[savageshooter86]

29.6 H4895 I get pressure in Alpha. 30” barrel using 105s. Velocity around 2960

 

[madmixerman]

I just shot 30.2 gr. today, still a little stiff bolt lift. May drop another tenth or so.

 

[Longtrain]

Weight and capacity may be the problem. A fellow shooter has found the same problem with Alpha’s Dasher brass. Loads that are no problem in Lapua formed brass cause sticky bolt lift in Alpha, had to lower the charge by half a grain to eliminate the problem.