Marks from Ejector and 308 load limits

[TwoRavens]

I just started re-loading so bare with me

My second batch of reloads for my Bushmaster 308 worked out pretty well, but a few of the cases had a small circular mark on the base where the ejector would hit it. A couple even had a bur raised. Is this normal, or something to worry about?

When I was looking up the load the 308 Win with 178gr bullets, I looked at the Hornady, Sierra and Lee manuals. The Sierra had the lowest maximum, then the Hornady, but the Lee starting load was higher than both the others maximums... Since I was using Hornady AMAX bullets I went with there figures and made up 20 each of:
39.2
40.2
41.2
42.2
43.2 (Recommended max from H manual)
of Varget.

I shot all five loads at 100 yds, witt one 5 shot group each.

As you can see the groups size got better as the load increased.

I'm pretty happy with the 43.2 load, and my next step is to shoot it at 200 yds and chronograph it (if it ever stops raining...), but since the Lee max rec load is something like 46gr, should I try a high loads untill I see pressure signs or a drop off in accuracy?

 

[30Cal]

What kind of brass? Military brass needs about a full grain less and load data is usually published for commercial brass.

Burrs and dings are par for the course with gasguns. But if the case is starting to flow into the ejector hole on the bolt face (probably see heavily flattened and cratered primers with that), then you probably should back off.

but since the Lee max rec load is something like 46gr, should I try a high loads untill I see pressure signs or a drop off in accuracy?

46.0grs Varget seems like a lot, especially behind a 178gr bullet. That would be pretty hot for a 168gr bullet. I'd highly recommend using a chronograph if you want to take a stroll into NearMax and Max Pressure country.

 

[TwoRavens]

Once fired Winchester brass (not military). Timmed to 2.003. No crimp.

However it did the same thing on Federal brass too.

No pressure signs that I could see. I don't have the Lee manual with me, so It could be the 168gr figure I am rembering for the max 46gr load.

A friend at the range said the shoulder looked a little 'rounded' and suggested it could be a headspace problem. I used a RCBS precision mic on a fired case and it read 0.002 over.

Like I said, I'm happy with the group at 100yds, so unless it gets a bad at 200/300 I think I'll stick with. What confused me was the differences between the recomended loads.

 

[newfalguy101]

Part of the difference is in the test platform each company chooses.

Hornady uses actual firearms to work up their data, therefore if they gat a gun with a tight or loose chamber, fast or slow barrel, it will make quite a difference in the published MAX ( which is MAX for their gun ) versus the MAX for your gun, which can be higher or lower.

I dont know what the other guys use, so I cant comment on that

 

[30Cal]

A friend at the range said the shoulder looked a little 'rounded' and suggested it could be a headspace problem. I used a RCBS precision mic on a fired case and it read 0.002 over.

That's a great tool for compairing fired/unfired, but it's not a substitute for a headspace gage. Your sized brass should be 0.002-0.004" shorter than your fired brass--a good figure for reliable functioning and case life.

I'll tell you what--I've seen more conflicting data with respect to Varget than any other powder. I don't know why that is.

 

[scotty]

Lyman 48th lists a max 44.0gr of Varget with a 178gr A-max bullet. This is with a universal receiver.

The 2006 Hodgdon annual manual lists a max of 45.0gr of Varget for both a 175gr Sierra HPBT and a Speer 180gr SP bullet. Both are listed as compressed loads. The firearm is not specified.

As long as you have a load that shoots well, running it over a chrono as well as trying it at a longer range would be a good idea. Accuracy is better than velocity.

 

[USSR]

I just started re-loading so bare with me

My second batch of reloads for my Bushmaster 308 worked out pretty well, but a few of the cases had a small circular mark on the base where the ejector would hit it. A couple even had a bur raised. Is this normal, or something to worry about?

When I was looking up the load the 308 Win with 178gr bullets, I looked at the Hornady, Sierra and Lee manuals. The Sierra had the lowest maximum, then the Hornady, but the Lee starting load was higher than both the others maximums... Since I was using Hornady AMAX bullets I went with there figures and made up 20 each of:
39.2
40.2
41.2
42.2
43.2 (Recommended max from H manual)
of Varget.

I shot all five loads at 100 yds, witt one 5 shot group each.

As you can see the groups size got better as the load increased.

I'm pretty happy with the 43.2 load, and my next step is to shoot it at 200 yds and chronograph it (if it ever stops raining...), but since the Lee max rec load is something like 46gr, should I try a high loads untill I see pressure signs or a drop off in accuracy?

TwoRavens,

Having used Varget and the 178gr Amax in the .308, I can tell you that your load in Winchester brass is not a particularly hot load. What's your cartridge OAL? Can you seat the bullet out farther, or are you restricted by mag length or chamber length? In my FN SPR using Hornady Match brass (similar to Winchester in case capacity), I was loading 46.1gr of Varget at a 2.845" OAL for 2750fps. Autoloaders are tough on brass, particularly commercial brass. In any case, since you are seeing ejector marks on the base, I wouldn't go beyond the 43.2gr load.

Don

 

[TwoRavens]

This is for a Bushmaster 308, so I'm restricted by mag length. I was seating to 2.795.

 

[USSR]

TR,

Yeah, I wouldn't go beyond the 43.2gr load with that brass. You might want to look around for some mil spec brass that will hold up better than commercial brass in your autoloader. Here's a real good deal (Link below):

SPECIAL BATCH, 308 REMINGTON MILITARY UNFIRED WAS RUN ON MACHINE THAT DETONATED THE PRIMER AFTER THE AMMO WAS TAKEN APART THE PRIMER POCKET IS NOT AS BRIGHT AS THE ORIGINAL BATCH BUT WILL WORK FINE, 500-29.99, 1000-54.99, 2000-$99.98(49.99M), WITH SCRAP PRICES BEING SO HIGH THIS IS PRICED lower than ONCE FIRED BRASS.

Using mil spec brass and surplus IMR4895 powder at $80 per 8# jug, I have found loads that are both accurate and economical.

Don

http://www.patsreloading.com