question on o a l ??seating into the rifleing

[acemisser]

If I want to expermint with seating my bullets out farther
than the manual specs,Do I have to reduce my powder
charge....I NEVER get into max loadings...I tried to stay
within the mid range..Thinking my 22-250 would be more
accurate if the bullets where out more..

I have read where one can get dangerous pressure by
doing this..So what do I have to look out for if I seat
them touch or just off the lands,etc....Thank you...John

[John_M]

acemisser, For purposes of my response, I use the acronyms OAL and COAL to mean the same thing-the overall length of the cartridge from the base of the case to the tip of the seated bullet. The OAL of the cartridge from the base of the brass to the tip of the seated bullet is almost a meaningless dimension except in determining if the cartridge will fit into the rifle's magazine. Do you have the tools necessary to accurately measure the length of the cartridge from the base of the case to the OGIVE of the seated bullet? Without these inexpensive but necessary tools, you are just guessing about the distance from the ogive of the bullet to the rifling in the barrel.

Hornady makes an OAL Gauge and Bullet Comparator which, when used together, will give you very accurate dimensions for bullet "jump" to the rifling. Sinclair and other manufacturers also sell such tools. Midway, Sinclair, Cabela's, and other internet ratailers usually carry these tools. Others on this site have described the home-made tools they use to measure this dimension. Conduct a search on this forum to find some good recommendations.

In my OPINION, there are about three ways you can develop unsafe pressures: 1) Exceeding the recommended powder levels as stated in various reloading manuals; 2) Excessive compression of the powder by seating the bullet too deeply. Over time, this excessive compression of the powder can also slightly "nudge" the bullet a little out of the case, making the OAL of the cartridge a bit longer; 3) Seating the bullet so it is forced into the lands with a near maximum powder charge. This practice can also make a "mell of a hess" when you have to extract the chambered cartridge before firing. Bullet is stuck in the rifling, powder is all over everything and one's face is very red with embarrassment, etc. Some experienced hand-loaders will disagree with my opinion on this third item.

I hope these brief comments will provide you with a few ideas to achieve the exact bullet seating depth you want.

[Nor Cal Mikie]

Measuring OAL can be a chore as most bullets out of the box have the tips banged up a bit so you have a hard time getting a accurate measurement becausr they very from one bullet to the next. Best to use the the proper tools and measure at the ogive. And you're limited by the mag length or you single feed.
All my loads are mid range and I start with all bullets seated into the lands. You can always go shorter. Stick to one length then work from there. And another limitation will be the throat length. You may not be able to reach the lands and still have enough bullet in the neck. That's where custom short throated chambers works best.

[darkker]

If I want to expermint with seating my bullets out farther
than the manual specs,Do I have to reduce my powder
charge....I NEVER get into max loadings...I tried to stay
within the mid range..Thinking my 22-250 would be more
accurate if the bullets where out more..

I have read where one can get dangerous pressure by
doing this..So what do I have to look out for if I seat
them touch or just off the lands,etc....Thank you...John

IF you want to stuff the bullet into the lands, WITHOUT working up a load(meaning using a non-jamed load) then yes, reduce the charge.

GENERALLY, if there is less "jump" then a bullet has a better chance of not getting "off angle" with the bore; meaning better accuracy.

IF you randomly pick a load, or use a previous load, but now JAM into the lands; Yes you can have dangerous pressures. Watch for case head strech(measuring pre and post firing measurements), and the often misleading primers for signs of pressure.
The "issue" associated with jamming a bullet WITHOUT working up to a load, is that the Ogive/bearing surface of a bullet is NEVER a constant measurement. There are manufacturing tollerances that cannot ALWAYS be exact on mass produced anything.

Personally how I do it:
Resize a case. DO NOT prime it, DO NOT charge it. JUUUUUST barely seat the bullet in the case. Drop it into the chamber and close the bolt. Don't slam the bolt home, but use a swift even pressure on it(you are jaming the bullet into the lands/ seating it into the case after all). Then extract it carefully, get your calipers and measure the cartridge OAL. I do this a few times to get an average number. Take your shortest reading, then seat your bullet an amount deeper. I personally use Lee's recomendation of 1/32", or 0.03125" DEEPER than your readings. Even with 175 match bullets in my 308 for 1,000 yards, I have not found any benefit to seating closer than that. YMMV.

[acemisser]

sounds good to me.I have all the tools for the process...Hornady campartive gage,Special case for measureing
oal,etc...But from what I see the only way you can get an exact measure ment is to have a special bushing
made for your die that uses the ogive everytime,instead of the tip of the boolet..Thanks for the info..

I knoiw I tried seating into the rifleing one other time and was blowing primers for some reason..Even had
a case stick a time or two as well?????

[acemisser]

Loaded up some mid range loads with H 380 and 55 gr V MAX
about 12 thou. off the lands..22-250....will try them tomorrow at 250 yards..

[supergolfer18]

not tryin to steal the thread but with the Hornady tool with the modified case to find max OAL, do you have to adjust your measurement to account for the different headspace between the modified case vs fired case from your rifle?

[acemisser]

no it's just a standard case that is drilled and tapped in the base to screw onto the tool...

[supergolfer18]

I know what the tool is. The modified case is not the same dimension as a fired case so I believe you should account for the difference to get accurate measurements

[thomae]

supergolfer18 (http://www.savageshooters.com/member.php?18799-supergolfer18) :

If you wish to be more precise, the short answer to your question is Yes.
You can solve this issue by drilingl and tapping a once fired piece of brass to serve as the modified case. It's easy enough to do and it does not require any precision tooling.

[acemisser]

I guess I am not understanding your question...

[supergolfer18]

acemisser: with that OAL tool from Hornady you probably got the correct modified case to go with the tool correct? Take that and measure the headspace on it. Now take a case that has been fired in your rifle and measure the headspace on it. I bet you the two will not be the same and have read you have to account for the difference between the two to get an accurate reading of distance to the lands on your rifle.

For comparison my 308 win hornady modified case measures 1.618" headspace. My fired winchester brass reads 1.621". So there is a difference between the two. So to be as accurate as possible need to account for this difference when you take your measurement