Full Length Sizing

[maverick5582]

Since I have received my Redding Type "S" bushing full length die I have been resizing the AA brass back to it's original length. Would it not be better to just "bump the shoulder back a few thousandths" than taking it all the way back to it's original length.

My cases are now in need of trimming after one firing. Their lengths are all over the place.

[seatleroadwr]

Just bump back about .003. That gives me reliable feeding and trimming is minimal although I routinely trim for each reloading.

[LRRPF52]

Shoulder Set-back
There have been some guys that have set back their shoulders very minimally to reduce over-working the brass, but you do have to be mindful when doing that with a self-loader, since the chamber needs a bit of slop to be reliable. As long as you know your chamber and can prove to yourself that you have enough set-back to allow reliable function.

Trimming
As to trimming, there are guys on the forum who own 3 or more Grendels, and have run brass through them 12 times, through different chambers, before even thinking about trimming. Just know where that point is in your chamber and if you are within it. If you are not jamming the neck into the throat, it isn't necessary.

If you look at the SAAMI drawings, the chamber length from breech face to the tip of the neck is 1.530". I just went down to my bench and checked several cases, to include multiple firings of Lapua, ALEX-A, Hornady, and PPU brass. Nothing was over 1.525", but that is within .005".

Then factor in chamfering & de-burring your necks. I chamfer the inside and outside of the necks, but I avoid over-chamfering, which some folks have gotten into trouble with when using powered tools for their neck-chamfering process, cutting into their bullet jackets during the seating process.

http://bulletin.accurateshooter.com/2007/05/neck-chamfering-and-bullet-jacket-shaving/

Depending on the brass hardness and thickness, I will make a specific number of turns by hand with my chamfering tool, and that is never more than 3 strokes, at a moderate pressure in my muscle memory. The powered stations that have depth set-up for this process can help you avoid grinding your necks into circular blades, so I think the best advice with chamfering is to lean on the side of very minimal force, without removing a significant amount of material.

This is another area where the .300" neck diameter for the Grendel's chamber comes into play, in that it is forgiving to reloaders. Screw around with no neck trimming in another .264" caliber, with a .295" or .292" inner neck, and once you hit that wall with a long neck from multiple firings, you're going to need to neck-trim, otherwise you have a neck-throat junction that will crimp the case neck into the projectile upon chambering, which will often spike the peak pressure.

[mseric]

Since I have received my Redding Type "S" bushing full length die I have been resizing the AA brass back to it's original length. Would it not be better to just "bump the shoulder back a few thousandths" than taking it all the way back to it's original length.

My cases are now in need of trimming after one firing. Their lengths are all over the place.

How are you measuring your fired and sized brass? What tool or comaprator(comparator) are you using.


Are you in need of trimming because they are to long (how long) or are you in need of trimming because they are not consistent? What do they measure?

[Whelenon]

An ammunition gauge, a must for reloading. I see Midway is out of stock, Alexander Arms also sells them.

http://www.midwayusa.com/product/277624/le-wilson-case-length-headspace-gage-65-grendel

[sneaky one]

Mav,
is the gun functioning fine? That is the key , here.
In 2008 I did a ton of research on this cal., before I clicked the ADD TO CART button. I forgot the site I found this data on-it basically said-trim to 1.515, after the first firing, and never really worry for 10- 12 shots thru. It has been stellar advice so far.

LR1955 has had good luck using that bushing die set. I bought a Forster FL set in 09 = happy guy here.

BTW, it seems like the case body never ever gets squeezed in by the die at all. Never had an issue.

In hindsight, I really want a Red. bushing set. But at time of purchase-Forst. dies = I didn't see them anywhere for sale. I was a Grendel rookie then...

An ammo gauge is a good add on for Santa's list , ho ho ho !

[Zach987]

LRRPF52, this makes perfect sense. I have a .264 LBC-AR chamber. My new unfired Hornady brass averaged 1.533. I didn't check for chambering and ejection by hand before shooting my first 5 shot group. When I tried to eject the next round, it was stuck so hard I had to tap on the charging handle with a wooden mallet. Factory amax functions perfectly. According to the print of the LBC-AR (PTG sourced reamer) overall case length is the same as the Grendel at 1.530. After pulling the bullets and trimming down to 1.507 as per the Hornady manual, empty sized brass ejects perfectly. Haven't had time to load the trimmed cases so I've just been using factory ammo.

[BjornF16]

LRRPF52, this makes perfect sense. I have a .264 LBC-AR chamber. My new unfired Hornady brass averaged 1.533. I didn't check for chambering and ejection by hand before shooting my first 5 shot group. When I tried to eject the next round, it was stuck so hard I had to tap on the charging handle with a wooden mallet. Factory amax functions perfectly. According to the print of the LBC-AR (PTG sourced reamer) overall case length is the same as the Grendel at 1.530. After pulling the bullets and trimming down to 1.507 as per the Hornady manual, empty sized brass ejects perfectly. Haven't had time to load the trimmed cases so I've just been using factory ammo.

Is 1.507 a typo?

AA reloading data shows 1.520" minimum; 1.526" maximum case length.

http://alexanderarms.com/images/pdfs/grendel_reloading.pdf

[NugginFutz]

Is 1.507 a typo?

AA reloading data shows 1.520" minimum; 1.526" maximum case length.

http://alexanderarms.com/images/pdfs..._reloading.pdf

Hornady's 9th edition says trim-to is 1.506". So, not a typo. (I don't know where they got it from.) When I first started with this cartridge, just over a year ago, I found so many different lengths, it drove me to drink. My best advice is to try and determine your particular chamber's depth, and keep at least .005" - .010" shorter. That should put you in the neighborhood of AA's lengths. I personally prefer leaving all the neck I can.

As an afterthought, I can also recommend the Wilson Case gauge. Use it, and you should stay out of the weeds.

[LR1955]

Since I have received my Redding Type "S" bushing full length die I have been resizing the AA brass back to it's original length. Would it not be better to just "bump the shoulder back a few thousandths" than taking it all the way back to it's original length.

My cases are now in need of trimming after one firing. Their lengths are all over the place.

Maverick:

Bumping Grendel brass is a requirement so bump the brass.

The Redding bushing dies were the first bushing dies to be sold for a Grendel other than custom jobs. We bought them because at the time we were using fireformed 7.61 X 39 brass, Wolf brass, and Lapua brass as we could find them on the market. Each of these brass types needed a different neck bushing because the thickness of the brass at the necks plus spring back differed greatly. You needed a bigger bushing for the IMI 7.62 X 39 brass than the Lapua and the Wolf tended to need even a smaller neck bushing. Even today you need a bushing type of sizing die if you intend on shooting anything but Lapua brass.

Personally, I have never experienced what you are with a full length die in any caliber which leads me to wonder what your standards are for brass length. You would be amazed at how well rifles shoot with brass of differing lengths, as long as the brass isn't jamming the neck into the throat. In other words, try to keep the length uniform but ensure the length is under maximum.

I have shot the same brass through three or four different rifles. I trim after about ten loadings and normally get about twenty shots per Lapua brass. About six from Wolf stuff. I don't bother to trim Lapua brass until I have shot it about ten times.

If your brass is stretching that much, it isn't a Redding sizing die but rather a poorly made chamber and or a diet of dangerously hot loads.

LR1955

[maverick5582]

Full Length Sizing

Maverick:

Bumping Grendel brass is a requirement so bump the brass.

The Redding bushing dies were the first bushing dies to be sold for a Grendel other than custom jobs. We bought them because at the time we were using fireformed 7.61 X 39 brass, Wolf brass, and Lapua brass as we could find them on the market. Each of these brass types needed a different neck bushing because the thickness of the brass at the necks plus spring back differed greatly. You needed a bigger bushing for the IMI 7.62 X 39 brass than the Lapua and the Wolf tended to need even a smaller neck bushing. Even today you need a bushing type of sizing die if you intend on shooting anything but Lapua brass.

Personally, I have never experienced what you are with a full length die in any caliber which leads me to wonder what your standards are for brass length. You would be amazed at how well rifles shoot with brass of differing lengths, as long as the brass isn't jamming the neck into the throat. In other words, try to keep the length uniform but ensure the length is under maximum.

I have shot the same brass through three or four different rifles. I trim after about ten loadings and normally get about twenty shots per Lapua brass. About six from Wolf stuff. I don't bother to trim Lapua brass until I have shot it about ten times.

If your brass is stretching that much, it isn't a Redding sizing die but rather a poorly made chamber and or a diet of dangerously hot loads.

LR1955

Well, I chambered the barrel with a Manson reamer that was made by an AA print. I used the roughing reamer, the followed by the finishing reamer. Then I used the Go gauge as a guide and took just enough off the chamber till the bolt locked into the lugs. I had the instructor of the NRA course I was taking check the fit of the bolt behind me. He said it was fine. The reamers were sharp, they were not worn at all. I used a floating reamer holder as well.

I do not have any answer yet. The LBC bolt I bought works fine now after I lapped it in. It picks up the brass and locks into battery fine. I do not have a forward assist on this upper as it is a DPMS.

L.E. Wilson sent me another case trimmer this week for fired cases and the brass fits fine in it so I can trim the case length. I just wanted to make sure the brass did not get pinched in the chamber.

The hottest load I have shot is 27.8 gr of 8208 XBR that averaged out at 2473 f.p.s which should work out to about 45,376 psi.

When I used the Hornady comparator I checked the new AA brass length close to the datum line and brought the brass back to that length on the first resizing.

In the past with my bolt guns I just bumped the shoulder backed 0.003" and everything worked fine. The Grendel is a shooter and I do not want to do anything to screw it up. As long as I do my part it has not let me down it shoots tight groups with 120 and 123 grain pills.

When something like this occurs I like to use the forum for a sounding board, there is enough experience here to help me figure these issues out. Thanks for all the input, guys.

Maverick

[mseric]

Hornady's 9th edition says trim-to is 1.506". So, not a typo. (I don't know where they got it from.) When I first started with this cartridge, just over a year ago, I found so many different lengths, it drove me to drink. My best advice is to try and determine your particular chamber's depth, and keep at least .005" - .010" shorter. That should put you in the neighborhood of AA's lengths. I personally prefer leaving all the neck I can.

As an afterthought, I can also recommend the Wilson Case gauge. Use it, and you should stay out of the weeds.

Hornady and Western got it from Bill Alexander.

From Bill A.

We made a mistake in our (AA) published figure for the case length. The chamber will easily absorb cases until they split but as most reloaders want a trim length I went with a figure that should not be exceeded and then a tolerance. ie once the case gets beyond 1.526 it should be trimmed back to between 1.526 -0.006. This is a reasonable tolerance for any small hand tool and a pair of cheap calipers.

Factory new brass is well short of the chamber transition and brass will rarely grow such that it demands to be trimmed. Hornady and Western both work from the case print so if in doubt use thier figure.

As we print updates to our load data we will correct our trim figures.

[cory]

Hornady and Western got it from Bill Alexander.

From Bill A.

We made a mistake in our (AA) published figure for the case length. The chamber will easily absorb cases until they split but as most reloaders want a trim length I went with a figure that should not be exceeded and then a tolerance. ie once the case gets beyond 1.526 it should be trimmed back to between 1.526 -0.006. This is a reasonable tolerance for any small hand tool and a pair of cheap calipers.

Factory new brass is well short of the chamber transition and brass will rarely grow such that it demands to be trimmed. Hornady and Western both work from the case print so if in doubt use thier figure.

As we print updates to our load data we will correct our trim figures.

Should the length of new brass not be the length trimmed to?

[mseric]

Should the length of new brass not be the length trimmed to?

They rarely are in any cartridge. IME they are usually a little short.

With all the past confusion with case length AA vs SAAMI vs Hornady, I purchased one of these and found the correct case length and trim to length for MY rifle.

http://www.sinclairintl.com/reloading-equipment/measuring-tools/case-gauges-headspace-tools/sinclair-chamber-length-gage-prod32925.aspx

[montana]

They rarely are in any cartridge. IME they are usually a little short.

With all the past confusion with case length AA vs SAAMI vs Hornady, I purchased one of these and found the correct case length and trim to length for MY rifle.

http://www.sinclairintl.com/reloadin...prod32925.aspx

I have never seen this product before, thanks for sharing