Forester Neck Sizer/Bump Die

Shooter88 · Apr 22, 2017

Hello all. I have a Remington 700 Varmint in .308. I have been experimenting with different loads of IMR4895 as well as bullet seating depths and think I have found a combination that works well using Speer 168gr bullets. I am trying to shrink my groups even more by making my reloads as customizable as possible to my rifles chamber. Anyways, I have been neck sizing only but after about 2 or 3 loads, the cases were getting harder to chamber which I figured was due to the shoulder. I bought the Forester die to bump it back a little (I was thinking like around .002") but it moved the shoulder back .007" which to me seems like a lot. I ran another case through my small base die and it moved it about .005". Am I off base thinking that .007" is a lot? Will that amount really make that much of a difference accuracy wise? The good thing is that the die seems very consistent.

Thanks for any help I can get.

Praeger · Apr 22, 2017

It is difficult to say whether .007" is a lot to bump back without knowing what the original FL shoulder length was. Using a comparator, measure the shoulder length of a FL sized casing. Then take a second measurement from the same casing after being fired once. Now you have a reference point. Reload that casing until it creates a sticky bolt - measure that and you'll have a good idea of the acceptable range of shoulder length for your chamber.

Measure after each firing, and you can track the growth of casing length and know when it gets close to your known extreme length, then bump back the shoulder. You may be able to go several reloads before needing to bump back the shoulder. With a factory barrel, I doubt you will see significant changes to group size from keeping the casing close to full chamber size. In my opinion, checking shoulder length is important not so much for accuracy, but so that you don't load up batch of rounds that are hard to chamber or extract. Your load development and seating depth (in that order) are what makes the biggest changes in group size.

I use Redding the Competition Shell Holder Set. http://www.redding-reloading.com/online-catalog/35-competition-shellholder-sets

With these, you use your existing FL die and the shell holder changes the shoulder length in .002" increments.

Shooter88 · Apr 22, 2017

Praeger said:
It is difficult to say whether .007" is a lot to bump back without knowing what the original FL shoulder length was. Using a comparator, measure the shoulder length of a FL sized casing. Then take a second measurement from the same casing after being fired once. Now you have a reference point. Reload that casing until it creates a sticky bolt - measure that and you'll have a good idea of the acceptable range of shoulder length for your chamber.

Measure after each firing, and you can track the growth of casing length and know when it gets close to your known extreme length, then bump back the shoulder. You may be able to go several reloads before needing to bump back the shoulder. With a factory barrel, I doubt you will see significant changes to group size from keeping the casing close to full chamber size. In my opinion, checking shoulder length is important not so much for accuracy, but so that you don't load up batch of rounds that are hard to chamber or extract. Your load development and seating depth (in that order) are what makes the biggest changes in group size.

I use Redding the Competition Shell Holder Set. http://www.redding-reloading.com/online-catalog/35-competition-shellholder-sets

With these, you use your existing FL die and the shell holder changes the shoulder length in .002" increments.

Dang...wish I would have known about those shell holders before I bought the die. Oh well I guess. The die has some other cool features so I suppose I'll keep it and see how it does.

Thanks for the information.

Pinecone · Apr 23, 2017

Just don't run the die down so far. You need to set the bump die for the proper set back.

A lot of long range shooters FL size every time, but just bump the shoulder back 1 - 3 thou. Your chamber might not be perfectly round (oval) or straight (banana shaped), so FL sized eliminates issues.

Shooter88 · Apr 23, 2017

Pinecone said:
Just don't run the die down so far. You need to set the bump die for the proper set back.

A lot of long range shooters FL size every time, but just bump the shoulder back 1 - 3 thou. Your chamber might not be perfectly round (oval) or straight (banana shaped), so FL sized eliminates issues.

Good point...not sure why I didn't think of that. I guess maybe because the directions didn't say anything about adjusting the die to change the bump. Through trial and error on some previously fired cases that were getting stiff to close a bolt on, I was able to set it at .002" and was consistent thereafter.

Pinecone · Apr 24, 2017

Unless the die maker has you send in a few fired cases, they have NO idea what a .002" bump is for YOUR chamber.

But some die makers will make a custom die to your requirements.

Sticky · Apr 24, 2017

Pincone is spot on... you need to adjust the die, just like a full length die when you are trying to set the shoulder back a specified amount. A couple thousandths is fine for a bolt rifle, I set back about .005" for a semi-auto like an AR. I just use my F/L die and measure the setback to set it up.

I primarily neck size only for my bolt action rifles, but if you are getting difficult extraction, be sure your load and oal are good and it could just be the cases need a bit of F/L resize to loosen em up again. As mentioned, there can be a lot of very minor imperfections in the chamber that can lead to issues if you don't fully (or at least mostly fully) resize fired brass.

4g64loser · May 10, 2017

I love my Forster bushing bump dies. As others have stated, set up the die to size as needed (sinclair, stoney point, redding, etc all make gauges and inserts to determine your headspace) and select bushing based on what gives you the best results (bolt gun) or what tension you need to keep the bullets in place (semi auto or lever gun). I use this die exclusively in a 6BR varmint gun (haven't had to FL size yet) and have had excellent, and consistent, results. I turn my case necks and as a result I know what bushing to select. You may need to go a thou smaller based on having out of round necks.

Difficult EXTRACTION is usually a sign of overpressure or something else wrong. Difficult CHAMBERING is a sign of body expansion (check case head/web area with micrometer before and after firing and before and after sizing) or insufficient shoulder setback during sizing. Depending on chambering and bullet selection, I often seat my bullets into the lands. While there is a tactile difference to bolt closure, it is not the same thing as a case that is too tight in the chamber. Given that your rifle is a factory chamber I have significant doubt that the headspace is tight. My only factory remington is just barely in spec, I can close the bolt halfway on the no-go. I have seen plenty of factory rifles that are out of spec. Measure your fired brass with a datum gauge and then on a concentricity gauge. Or cerrosafe cast your chamber and gauge the casting. You are likely to find a loose chamber and a VERY long throat.

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