cartridge stuck in breach

tsapelak · September 15, 2009, 06:24 AM

recently new to reloading. Just completed my first batch of 308 rounds and Have found several rounds that will not allow he breach to close completely. I have mic`ed the cartridges and compared with other fired rounds that loaded properly and compared to correct sizing in refference material. they are the same or .01-.02" smaller. Have also sperated case brands with no correlation found.
Shooting a DPMS AP4 308, Hornady A-Max 155gn bullet loaded with 40.6gn of
Hodgdons H4895.
Any Ideas?

dardascastbullets · September 15, 2009, 06:51 AM

Hi tsapelak,

You have indicated in your post that you 'mic'd' your cartridges. By what method did you mic your cases? With an RCBS Case Gauge, Stoney Point? Your problem is indicative of a case headspace problem. To prevent the problem that you are experiencing, I will suggest that you look into purchasing one of the above two items. There are others available - these are just a representative sample.

Good luck with your shooting!

Sport45 · September 15, 2009, 06:53 AM

Welcome to The Firing Line!

Quote:

Any Ideas?

Yes, screw the sizing die in a little more.

About the easiest way to ensure they will chamber is to get a case gage and check all of your brass in it after sizing and again after finishing the round. I use a Lyman case gage for all my M1 and AR loads.

Sevens · September 15, 2009, 09:21 AM

Take a sized and trimmed piece of brass that is not yet loaded and chamber it. Does it give resistance, or smooth sailing?

If it resists, you aren't sizing it enough. If it's good to go and chambers and extracts with no problem, then seat a bullet.

NOW chamber it. Resistance? Tough going in and tough coming out? Look at the bullet and check for scuff marks on it. Seating some bullets too far out (depending on the bullet profile) and they will make contact with the rifling and you end up with rounds that won't chamber... worse are the ones that don't want to extract. Can get to the point of plucking the bullet from the case and dumping a full charge of powder in to the guts of your rifle.

Don't make any large batches of ANYTHING until the first couple fit your magazine and fit your chamber. Even then, don't make a huge batch until you've range tested them to make sure they function the rifle and are safe. If you made 20 of them or 100 of them and they aren't any good, you've got a LOT of work on your hands to disassemble them.

GeauxTide · September 15, 2009, 12:48 PM

For an autoloader, consider the RCBS Small Base dies.

tsapelak · September 15, 2009, 06:23 PM

I appreciate your replies and will check head space. Will also disassemble each round causing the problem and then see if the blank casing loads and ejects smoothly. I`m using a digital mic to check neck to base demensions. The fact my readings are less than fired rounds seems normal as fired rounds expand slightly but may mean the head space thought may be a good one.
I`ll let you know what I find.
Thanks

dmazur · September 15, 2009, 07:55 PM

Quote:

I`m using a digital mic to check neck to base demensions.

No offense intended, but how are you setting that up? Digital or not, calipers or a mike can't easily (repeatedly) measure to a datum that is halfway down the neck. That datum is one end of your headspace, with the bolt face being the other.

If you really are measuring 0.010" to 0.020" of difference, the question to ask is, "How did the brass get that long?" If your rifle permitted it to expand that much, it has excessive headspace. Perhaps dangerously excessive.

As an alternative to the Stoney Point type of headspace measuring tool, you might consider the Wilson type cartridge headspace gauge. While this gauge is typically used as a visual check of the cartridge head to see if it is between "steps" that are machined 0.006" apart (usually), it can also be used with calipers to measure cartridge headspace difference between once-fired brass (in your rifle) and brass that has just been resized. To maximize brass life, many recommend resizing 0.002" or so under actual headspace.

Reloading for several rifles in the same caliber can make things more challenging, if you don't want to segregate cartridges. One approach is to 1) make sure all the rifles are in SAAMI spec for headspace, and then 2) resize so your cartridge headspace length also falls within SAAMI specs, and 0.002" or so shorter than the shortest chamber.

My limited understanding of headspace issues is that 0.006" for a firing/resizing cycle isn't ideal for brass life, but it isn't dangerous.

steve4102 · September 16, 2009, 07:11 AM

Two things, first you did not mention what type of sizing you are doing. If you are neck sizing only, DON"T. It will not work in a semi-auto. You must FL size. Second, if you are FL sizing, as stated above, you do not have the sizing die set up properly. Raise the ram, screw the die into the press until it touches the shell holder, lower the ram, screw the die IN 1/4 turn more.

Check to see that the newly sized brass(no bullet) cycles in the action. If it does, seat a bullet(no primer/powder) and see if it cycles in the action. If not then you have your seating die set up incorrectly. Raise the ram, screw the die into the press until in comes in contact with the shell holder. Lower the ram screw the die OUT one full turn and lock the nut.

RKG · September 16, 2009, 08:30 PM

While I do not disagree with the wisdom set forth in prior replies, I do add that another possible issue is cases in need of trimming.

harabas · October 22, 2009, 05:08 PM

Just bought a DPMS 243LR and had the same problem. I had to buy a small base resizing die and then seat the bullets to 2.60" which is deeper than I wanted. My DPMS has a very tight chamber. These bullets fed well. Next, I'm going to full length size this same brass afrer firing and these should feed ok, being shot in the same rifle. Depth of seating is very important in these rifles.

September 15, 2009, 06:24 AM	#1
tsapelak Junior Member Join Date: September 15, 2009 Posts: 2	cartridge stuck in breach recently new to reloading. Just completed my first batch of 308 rounds and Have found several rounds that will not allow he breach to close completely. I have mic`ed the cartridges and compared with other fired rounds that loaded properly and compared to correct sizing in refference material. they are the same or .01-.02" smaller. Have also sperated case brands with no correlation found. Shooting a DPMS AP4 308, Hornady A-Max 155gn bullet loaded with 40.6gn of Hodgdons H4895. Any Ideas?

September 15, 2009, 06:51 AM	#2
dardascastbullets Senior Member Join Date: July 20, 2008 Location: Essexville, MI Posts: 164	Cartridge Problems Hi tsapelak, You have indicated in your post that you 'mic'd' your cartridges. By what method did you mic your cases? With an RCBS Case Gauge, Stoney Point? Your problem is indicative of a case headspace problem. To prevent the problem that you are experiencing, I will suggest that you look into purchasing one of the above two items. There are others available - these are just a representative sample. Good luck with your shooting! __________________ Matt Dardas

September 15, 2009, 09:21 AM	#4
Sevens Senior Member Join Date: July 28, 2007 Location: Ohio Posts: 11,756	Take a sized and trimmed piece of brass that is not yet loaded and chamber it. Does it give resistance, or smooth sailing? If it resists, you aren't sizing it enough. If it's good to go and chambers and extracts with no problem, then seat a bullet. NOW chamber it. Resistance? Tough going in and tough coming out? Look at the bullet and check for scuff marks on it. Seating some bullets too far out (depending on the bullet profile) and they will make contact with the rifling and you end up with rounds that won't chamber... worse are the ones that don't want to extract. Can get to the point of plucking the bullet from the case and dumping a full charge of powder in to the guts of your rifle. Don't make any large batches of ANYTHING until the first couple fit your magazine and fit your chamber. Even then, don't make a huge batch until you've range tested them to make sure they function the rifle and are safe. If you made 20 of them or 100 of them and they aren't any good, you've got a LOT of work on your hands to disassemble them. __________________ *Attention Brass rats and other reloaders:* I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.

September 15, 2009, 06:23 PM	#6
tsapelak Junior Member Join Date: September 15, 2009 Posts: 2	Good advise I appreciate your replies and will check head space. Will also disassemble each round causing the problem and then see if the blank casing loads and ejects smoothly. I`m using a digital mic to check neck to base demensions. The fact my readings are less than fired rounds seems normal as fired rounds expand slightly but may mean the head space thought may be a good one. I`ll let you know what I find. Thanks

September 15, 2009, 12:48 PM	#5
GeauxTide Senior Member Join Date: April 20, 2009 Location: Helena, AL Posts: 4,424	For an autoloader, consider the RCBS Small Base dies.

September 16, 2009, 07:11 AM	#8
steve4102 Senior Member Join Date: December 23, 2005 Location: Minnesota Posts: 2,955	Two things, first you did not mention what type of sizing you are doing. If you are neck sizing only, DON"T. It will not work in a semi-auto. You must FL size. Second, if you are FL sizing, as stated above, you do not have the sizing die set up properly. Raise the ram, screw the die into the press until it touches the shell holder, lower the ram, screw the die IN 1/4 turn more. Check to see that the newly sized brass(no bullet) cycles in the action. If it does, seat a bullet(no primer/powder) and see if it cycles in the action. If not then you have your seating die set up incorrectly. Raise the ram, screw the die into the press until in comes in contact with the shell holder. Lower the ram screw the die OUT one full turn and lock the nut.

September 16, 2009, 08:30 PM	#9
RKG Senior Member Join Date: June 18, 2009 Location: Boston Posts: 562	While I do not disagree with the wisdom set forth in prior replies, I do add that another possible issue is cases in need of trimming.

October 22, 2009, 05:08 PM	#10
harabas Junior Member Join Date: October 21, 2009 Location: Las Vegas, NV Posts: 3	Just bought a DPMS 243LR and had the same problem. I had to buy a small base resizing die and then seat the bullets to 2.60" which is deeper than I wanted. My DPMS has a very tight chamber. These bullets fed well. Next, I'm going to full length size this same brass afrer firing and these should feed ok, being shot in the same rifle. Depth of seating is very important in these rifles.