Stiff bolt close? Why

[apache12]

So I've been loading for less than a year but have done a fair amount of loads and have learned some but this one is new to me

 

Why would some rounds be a bit stiffer to close the bolt? It like the bullet is jammed in the lands but I see no evidence of that

And. It happens with the same type of brace that have all been run through a full size and trimmed and prepped and cleaned in the same batch.

 

I'm very good about measuring after seating each load

 

I haven't noticed a difference in accuracy at the range but I haven't shot enough of these to be real sure

 

I load bolt action rifle only so far

 

Is it he shoulder?

Am I closer to the lands than I think and any small variance makes a difference?

I have noticed anything odd on spent cartridge

 

Thanks for any tips

[lancetkenyon]

Trimmed case length? Even .001" too long will cause the case to jam into the throat. This will definitely cause a hard to close bolt. Trim to .0100" below SAAMI case length or chamber reamer length.

 

Shoulder bump? With a standard shell holder, you get a little difference from case to case depending on how hard it is to resize. This can cause .001" or even .0005" shoulder bump difference, possibly causing it to touch the end of the chambering. If you load to very tight tolerances, this can cause hard to close bolts. Bump shoulder back .002" more.

 

Bullet jammed into the lands? Even the best bullets (SMKs, Berger HVLD or Hybrids, Lapua Scenar) can have just a bit of meplat difference. If you don't measure to the ogive, you can touch lands on occasion. This can cause stiff bolt closure. Seat bullet another .0020" deeper.

 

Dirty lugs? A small amount of grit in the lugs or action can cause stiff bolt close. Clean action & bolt.

[HuntHarder]

In my experience, this is usually caused by improper sizing of the brass. Adjust your resizing die down a slight bit, and resize the brass. Then try and chamber just the empty brass to be sure you resize it enough. Some chambers are looser than others, and the brass will expand differently.

[Pine Donkey]

My guess is that if it is all cartridges causing the problem you need to bump the shoulder just a bit more. If it is just some of them causing the problem, take a close look at you case length and trim it if needed.

[Chimichanga]

+1 for bumping the shoulder more and full length resizing..

[Hoss50]

I had this issue with my 257 weatherby. I was loading 7mm mag brass so there is no way the case is to long. The bullet was seated to far out and jammed the lands.

 

I have also had this problem with 3006 and that was from the cases being to long.

 

Harley

[Titanium700]

Yep.

Bump the shoulder back a bit

[willhunt4coues]

Get the correct tool to measure how much YOU BUMP though. If not you may OVER due it.

It does sound like you may not be bumping enough. But JUST TAKING the die and turning it can over due what you don't want to.

Get this comparator set so you know for a fact to only bump .002 to .003.

http://www.midwayusa.com/product/479704/hornady-lock-n-load-headspace-gage-5-bushing-set-with-comparator

[apache12]

Thanks. I'll get the tool

 

So to bump to I twist the die a little lower than just touching the shell holder when I raise the cam?

[Pine Donkey]

The tool is the best way. Another thing that works, until you get a tool, is to lightly spray the shoulder/neck with spray foot powder. Size a piece of brass and determine how far down the neck the die is sizing. Turn your die ever-so-slightly and recheck. Once you have a good depth, clean the cartridges then chamber them as a final check.

 

Be very cautious not to move the shoulder too much. After shooting a round check around the outside of the base for any signs of gas leakage or cracking. If you see any signs, you went too far.

[azgutpile]

What is your procedure for setting up your resizing die? (e.g. Touching the shell holder, or 1/8 to 1/4 turn past touching?)

[apache12]

I raise the ram and then thread the die until it touches the shell holder. Then tighten. That's what I've been doing

 

So should I lower the cam and thread a little lower?

Powder trick sounds good

[sherman]

I would say you need to make it touch then 1/8 turn down so it bumps it back just a bit more

[willhunt4coues]

1/8 of a turn will be too much. When bumpiing you will be doing JUST THAT BUMPING. All dies are different. I noticed on mine I made little marks at 1/16" at the bottom of the die. Each 1/16" was about .001 bumping so you BARELY even turn the die.

I tighten my lock ring then lock the lock ring down then I size, if not right loosen lock ring and barely turn 1/16" then tighten lock ring then re-tighten the die. keep doing this till you get a bump.

I take all my fired brass and see if any are tight in chamber if so take note of the CBTD (cartridge base to datum) usually this will be the same number over and over letting you know your chamber CBTD. Then set in Die to only BUMP .002 to .003. I have found .002 is VERY accurate and every round chambers perfectly. Watch some videos online to understand better. I will try and find some for you.

[willhunt4coues]

Read this some dies just can't bump. I use Whidden

http://www.accurateshooter.com/technical-articles/die-issues-when-bumping-shoulders/