I am trying to work up a match load for the first time. I am using Hornady 68gr hpbt match bullets. I have read that for optimum accuracy, you should seat the bullet within .0060 of the lands. Lacking a guage, I first tried to underseat the bullet in a test case and let the action finish the job. The plan was to measure the result and back it off about .0015. A good plan until I extracted an empty case and left the bullet in the chamber.

Plan two was to seat the bullet so the length was 2.260, which is what the book lists as maximum. The result was that the action needed the forward assist to go all the way home, and I had great difficulty extracting the round. So much so that I had to gently pry the bolt carrier up from the rear.

What is going on? I have a mil-spec Rock River, it should at least have a chamber long enough to handle the max recomended length.

I have two thoughts. One is that the load data I was using was for .223 Rem. and 5.56mm has a longer leede. That should have the opposite effect, but what do I know.
The other is that there was a little extra oil in the barrel, and this might have caused the cartridge to be sticky on the eject cycle.

My plinking load is a 55gr fmjbt with an overall length of 2.245 and it cycles fine.

Any help would be GREATLY appreciated.
EV

I think the 2.260 is listed as max because that is the magazine constraint on GI 20 and 30rd mags. I seat all my 69's and 77's to that length, but my 80's I seat out like MX missiles in my Colt chamber they have to go out a long way...to get within .010" of the lands.

Mike

------------------
Victory Through Superior Firepower!

El Viejo,

There is a simple way you can determine the maximum overall cartridge length for your specific rifle. It takes a cleaning rod with a FLAT tip, a short rod like a section of a cleaning rod, a couple of pieces of masking tape, a sharp knife and a magic marker.

Close the action and don't pull the trigger. Put the cleaning rod with FLAT tip down the muzzle until it touches the bolt-face. Put one piece of masking tape on the rod at the muzzle (half in and half out). With the cleaning rod against the bolt-face, place the knife flat against the muzzle and make a scribe in the masking tape. With the magic marker, mark across the knife mark and wipe the excess wet ink off. That will leave a small dark mark that is the length from the bolt-face to the muzzle. Next, drop a bullet into the throat and gently push it into place against the rifling with the short rod. Then again put the same cleaning rod with flat tip into the muzzle and down the bore until it touches the bullet tip. With the cleaning rod and the short rod you can move the bullet back and forth as it touches the rifling until you get the amount of engagement against the rifling that you want. Again put masking tape on the cleaning rod half in and half out of the muzzle. Again make a knife mark on the masking tape, color it with magic marker and wipe the excess ink off. You now have two black knife marks on the cleaning rod that are the distance from the bolt-face to the tip of the bullet. That distance is the maximum overall cartridge length for that rifle with that bullet. Measure the distance between the two marks on the cleaning rod and from that distance subtract whatever bullet set-back you want. THEN - - LOAD A TEST ROUND AND MEASURE THE OVERALL LENGTH WITH THAT BULLET. Use that bullet, because there are slight diferences in bullet length - especially with exposed lead tips. It is then best to measure that test load with a comparator, and note the overall length including comparator for future load setups.

It's cheap and easy and can be done to a thousandth on an inch.

Good shooting

Don Shearer

Very good explanation Don. I use the same method and it works much better than the Stoney Point widget. Only thing I'd add is that it can help to have a helper keep the short rod/dowel against the base of the bullet in the chamber until you get the other rod up against it, especially in rifles with long barrels.

Roger

Hey Don and Roger:

I'm new to handloading and in fact, am about to take the plunge and purchase the stuff I need to get started (a Rockchucker Master Kit and some accessories). The process you are describing here--am I correct in concluding that it takes the place of the Stoney Point OAL Gauge? If so, that would be great, and would save me the $30 or so I was going to spend on that gizmo.

If you have any other tips/tricks that can be used in place of buying accessories, bring them on!

Thanks...

Don and Roger,
Thank you both for the help. An effective and inexpensive method, much appreciated.

One of the things that is constantly on my mind is to avoid blowing up my rifle. I have some concerns about how close to the lands I can seat the bullet before a normally safe load becomes a bomb. Any thoughts on this would be most welcome.

Thanks again for taking time to answer.

El Viejo,

Well, seating the bullet into the lands does increase the breech pressure, but honestly, I think that factor is quite overblown. As long as you are dealing with loads that are not already up to max. I don't think you have to worry. I would be a bit cautious and set the bullets back a few thousandths for loads that are max book, but those that are even as much as a grain under, you could put the bullet hard into the lands if you want to do that.

I have done a lot of load development for Mike Bellm's Triad for the Contender (14")and have found the most accurate loads for all three (the 7mm, 308 and 358) are with the bullet set just to touch the rifling. With all three of these wildcats, I did monitor the pressure with work-up loads and really didn't see any significant jump in pressure due to setting the bullet against the rifling.

Good shooting

Don Shearer

Thanks Don.

Crusader,

Yes, this method does take the place of any other OAL gauge. In fact I don't own an OAL gauge yet I always measure for Max OAL and bullet setback with every bullet I load. It's so easy.

Good shooting,

Don Shearer

El Viejo

You can have the bullet "hard into the lands" and still be safe as long as you start low and work up while doing it....My buddies Krieger barreled AR shoots the 80gr SMK's best that way...I seat mine .010" off the lands..

Mike

An update on the match loads.

I worked up the load, and there is no powder combination which gives a good group in my rifle. The BEST group was 2". I have come to the conclusion that a 68 gr bullet won't stablize in my 16 inch 1 in 9 twist.

I am thinking of going to a A Max 52 gr. We are shooting a 100 yd reduced target match.
Any comments?
Txs

------------------
Never teach a pig to sing.
It wastes your time and annoys the pig

Good advice by all. There was a good string on the same topic about two weeks ago. (4/24)

The only thing I add is when you determine optimum OAL for each bullet choice, load a dummy round with no primer and keep it handy for setting your seating die up next time.

Cheers, Mike