.308 reloads won't chamber - suggestions?

[runway1]

I hope I can describe this accurately. Some background; Remington 700P, .308, target shooting at Angeles to 600yds. Very new rifle (<300 rounds), fires well, all stock, several groups at .38, .44....most all well under .70 MOA.

Ok, reloaded a batch of 50 rounds, SMK-150gr. Bracketed three loads just under the Hornady manual redline. Ok, no problem, shot awesome with 42.3/42.5 gr load - .38 MOA at 100 yds. Hitting 400 yd steel like it was the side of a barn. 43.5/43.7 shot about .5/.6 MOA at 100 yds - great.

Went to the gun show and bought 100 rnds of mixed brass. It measures all fine (I use a Mitutoyo calibrated...meaning folks at work get paid to make sure it's correct.. 6" digital caliper). Case lengths, ODs at all points, etc. all are dead on. STUFF WON'T CHAMBER! NOTE: The only measurement I can't perform is the shape of the neck. Given its angle, I just can't take a straight, linear measurement that makes sense.

At Angeles, the fellow in the relaod shop asked me to mark (Sharpie pen) the length, chamber it (best possible) and check for mark-off in the bad places (neck & bottom). Nothing unusual.

Next fellow (same place, same day) checked head space with an RCBS tool mounted onto RCBS calipers - all seemed ok with the headspace measurements.

Ideas? It's a learning thing only. Worst case, I throw away 100 rounds but big deal.....I WANT TO KNOW WHY! I appreciate the inputs. Thanks all!

[Sub95]

the shoulder needs to be bumped down some more.

take a good round that will chamber and put it next to one that wont and look at the shoulder.

[Point of Impact]

Measure the headspace on a round that will chamber and compare it to a round that will. I would use an rcbs precision mic or a hornady headspace tool.

[Spanky8601]

the shoulder needs to be bumped down some more.

take a good round that will chamber and put it next to one that wont and look at the shoulder.

Plus on this. You full length sizing die most likely needs to be dialed in just a little more.

[Taildraggerdave]

Plus on this. You full length sizing die most likely needs to be dialed in just a little more.

This too ^^^

Run your sizing die down in increments until a couple pieces chamber in your rifle. Then you should be good.

After you fire them in your chamber, you can actually go back up on the sizing die until the die just bumps the shoulders back on cases that have already been through your rifle.

In fact, you can probably get away with neck sizing only, after they've been through your rifle at least once.

Take care,
Dave

[G-forceJunkie]

You need to size the brass properly (More in this case.) You may have gotten brass fired out of a loose chamber and it really expanded. Next time, try loading the empty brass into your rifle after sizing it. If it doesnt fit, size it more.

[bruceflinch]

You need to size the brass properly (More in this case.) You may have gotten brass fired out of a loose chamber and it really expanded. Next time, try loading the empty brass into your rifle after sizing it. If it doesnt fit, size it more.

Possible he got some former machine gun shot brass?

Don't throw away that ammo. The bullets can be pulled & brass resized & reloaded. Anyone who reloads 308 could fix it.

Nothing else to add that hasn't been already said.

[runway1]

the shoulder needs to be bumped down some more.

take a good round that will chamber and put it next to one that wont and look at the shoulder.

Did that, measured all that I could, two others did the same - with endless years of reloading experience - no obvious indications.

[runway1]

Measure the headspace on a round that will chamber and compare it to a round that will. I would use an rcbs precision mic or a hornady headspace tool.

As mentioned, the fellow at the shop did exactly that per the RCBS standard dims, with RCBS tools - no indication of any out of tolerance issues.

[runway1]

You need to size the brass properly (More in this case.) You may have gotten brass fired out of a loose chamber and it really expanded. Next time, try loading the empty brass into your rifle after sizing it. If it doesnt fit, size it more.

That's what I'm thinking at this point. Problem is, I reset the full-size die and ran some "problem" cases through, empty, and still the same issue! Some made it though, which really is confusing me

[Bladeshark]

I had the very same problem with a batch of .308 I loaded up. I'll be watching this thread for hopes of a solution.

[gunboat]

You may need a small base die -- could be some of the brass fired in an auto --

[Sub95]

you are only talking about .001 -.002 thousands off, so you need to really look from the shoulder to the neck.

if you take a loaded round that loads easy and put it next to one that wont load, you will see the shoulder is a different shape.

[runway1]

you are only talking about .001 -.002 thousands off, so you need to really look from the shoulder to the neck.

if you take a loaded round that loads easy and put it next to one that wont load, you will see the shoulder is a different shape.

I've done the visual with many and I think you're right although, .001/.002 is not discernable with an eyeball. I think you're right is just that.

[runway1]

You may need a small base die -- could be some of the brass fired in an auto --

I wasn't concerned buying once-fired brass thinking "it's going to be resized anyhow". But you're the second person to mention that.