The MIGHTY Power of a Primer Change

[T-shooter]

It's difficult to rate a 2 0r 3 shot group. When you are getting close, do 5 shot groups and when you thing you have it, do a 10. Have a few extra rounds with you in case you pull a shot, just reshoot that particular one.

 

[Coyotefurharvester]

I was going to try a primer change in my new 22-250. The brass I had been using the primer pocket was a couple thousandth shallow, I had to uniform the Nosler brass to fit a Rem primer, CCI br seated fine, Rem was .001-2 proud. I noticed it when chamber checking a finished round without the firing pin assembly.

 

[dogdude]

Like too here about the CCI-250 !

 

[Ledd Slinger]

It's difficult to rate a 2 0r 3 shot group. When you are getting close, do 5 shot groups and when you thing you have it, do a 10. Have a few extra rounds with you in case you pull a shot, just reshoot that particular one.

Never fired a 2 shot group in my life because that is not a group at all. The two shots you see on in the one target pic were quick fouler rounds fired with little attention paid to precise aiming. Not intended to as a group whatsoever. If you read closely on the original post, I fired a second 3 shot group to confirm accuracy of the first 3 shot group. The rifle produced 2 one hole groups with 3 rounds each.

And have you ever fired a 10 shot group with a large magnum rifle burning around 90 more grains of powder in each case??? The barrel gets pretty damn hot even after 5 rounds. No way will I ever fire a 10 shot group with this rifle. That's just asking for a ton of accelerated barrel wear. Absolutely no need for that in a hunting rifle.

The biggest thing I pay attention to with hunting rifle groups is whether or not the first cold bore shot falls in with the next two. Cold bore first round shots are by far the most important aspect for a hunting rifle.

 

[mikecr]

Seems like blind luck so far.
But you know from past experiences that no primers are actually 'better'.
So there is an explanation for differences amid the abstracts here, that is unlikely the primer choice itself.

I'll throw in a suggestion that the difference in this case may be your primer striking.
That if this was adjusted with testing (by itself) the Feds could close to similar results with Rems.
This may seem odd with all primers firing just fine, but obviously there is more to primer results than merely firing.

 

[Dud]

Luck is fine but you need to test if you want to understand what you found, that's why I think you should run OCW ladders with both primer types.

As for the primer striking, a friend of mine had a rifle with the firing pin hole machined off center. Accuracy sucked but then he found one type of primer that occasionally didn't fire when it got hit off center. That led us to investigate the bolt which was replaced by the manufacturer. That solved the ignition issue and the accuracy which seems to have been poor due to inconsistent ignition.

My friend didn't find a magic primer, he found a mechanical issue.

Until you test, you don't understand so the learning doesn't apply for anyone but you.

 

[CT10ring]

There are always so many threads about
"what powder to use with such and such cartridge" or "what bullets is best for this and that"

Although there seems to be some certain powders that do actually work quite well with certain rounds, I have always told folks to try as many powders and bullets as they can that will fit the rifle's application. This ensures the best accuracy is not accidentally overlooked.

It is well known to most folks that a primer change in a load can have a massive effect on accuracy as well and I have witnessed this many times personally in the past. But to be brutally honest with myself, I have always had a strong bias towards ONLY using Federal primers in my rifles. I have always carried many different primer brands on the shelf for testing just in case I couldnt find a load using Federal, but didnt use them extensively because Federal always worked out in the end.

Well I decided to start doing initial load testing a little different this time with my new 300 NMI hunting rifle. Just to put a spin on things if nothing else.
I loaded all the starting recipes like i normally would using Federal GM215M primers, but then I loaded another set of rounds with the same exact recipe save for changing the primer to a Remington 9 1/2 Magnum. The results were astonishing...

These are only 100 yard groups and only a couple I've tried so far, but the difference is night and day.
In the first photo, I probably would have completely dismissed playing with the 90gr charge of RL33 had I only tried the GM215M primer, but look what happened when all i did different was use a Rem 9 1/2M in the same recipe. The accuracy changed from about a 1.5+" group to a sub 1/4" group.

View attachment 1126518

View attachment 1126519

I then fired another 3 shot confirmation group at a different target using the same recipe with the Rem 9 1/2M to ensure the first group wasnt a fluke. I think this group was even smaller.

View attachment 1126521



The next test was using the same two primers in a load using an identical charge of N570. In this instance, the GM215M performed better. The difference wasnt as drastic, but most definitely noticeable on the paper.

View attachment 1126522

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I suppose the point of the topic is to recommend people pay as much attention to testing different primers in a load as they would any other component. As this test confirmed (along with my other past experiences), a primer change can have a massive effect on how a rifle shoots. The primer changes shown above took bad groups and gave them acceptable accuracy. So where I normally may have moved on to the next load due to poor accuracy, the differences made me stop and think, "wait a second, I DO have something to really work with using this powder".

great info! super shooting. I only use CCI primers (?). lotta variables. Cool to see the amazing accuracy change.

 

[Ledd Slinger]

For the CCI fans, I have also seen rifles shoot loads with CCI better than other primers. If the Fed GM215M or Rem 9 1/2M didnt show promise, the CCI 250 would have been my next choice.

I also carry a full array of small rifle primers for the same type of testing in varmint/target rifles. Fed 205, Fed 205M, Rem 6 1/2, Rem 7 1/2, CCI 400, CCI 450, CCI BR4, and Winchester SRP.

I wouldnt say any type of primer is better than another primer as they can all produce accurate loads.....Wait, I take that back.
ANYTHING is better than Winchester primers. Never once have I seen a Winchester primer shoot better with any given powder in any rifle when compared with Fed, CCI, or Rem.

 

[Ledd Slinger]

Ledd,

Hey, where are the pics of the new rifle? This thread can't be complete without them!! Looks like you are off to a great start. Looking forward to more results.

Paul

Only have pics of it before I mounted the scope. Will have to take some more pics with the Spuhr and Trijicon 4.5-30x56.

The Titanium 4 port BEAST brake that Alex Wheeler installed is amazing (he also chambered the barrel). With the bipod dug in the dirt, this thing barely kicks at all! A small toddler could shoot this rifle.

 

[Ledd Slinger]

Here you go Paul - @boltfluter

Snapped a few quick photos for you. Not sure if you remember the rifle specs so I listed them below as well.

Chamber: 300 Norma Mag Improved, .339" neck (my own chamber design specs)
Reloading Dies:
Sizer - Whidden custom FL neck bushing sizer and custom 30 cal expander ball set.
Seater - Wilson inline Micrometer seating die blank custom cut with my chamber reamer.
Action: Kelby's Altlas Tactical - Lapua, with 20 MOA pinned scope rail (bedded with Marine Tex), aftermarket custom bolt knob.
Barrel: Proof Research carbon fiber, .308 cal 1 in 9" twist, Sendero contour, 26" long.
Brake: Muzzle Brakes & More Titanium BEAST 4 port, seamless flush mount
Stock: AG Composites all carbon fiber 'Chalk Branch', bedded to action with Marine Tex.
Trigger: Bixn' Andy TacSport PRO set at about 6 oz.
DBM: PT&G 700 drop in with 5 round Accurate Mag and custom inner trigger guard mag release knob.
Scope: Trijicon Accupower 4.5-30x56, factory custom Tenebraex caps, Lone Star 34mm level
Scope Mount: Spuhr 34mm, rings bedded to scope tube with JB Weld.
Bipod: Reproduction of the LRA carbon fiber Light Tactical bipod.

 

[boltfluter]

Ledd,

Thank you for the pics! Awesome looking rifle. This should be a
T-rex slayer!

Paul

 

[Ledd Slinger]

Just got in some 500 yard shooting. Turns out the 100 yard RL33 group with Rem 9-1/2 M didnt work very well at 500. l mean it shot 2.5" to 3", but the vertical was really bad. That's why I dont trust 100 yard groups.

I also shot some N570 groups with the GM215M primer. They shot much better with good vertical.

Shooting decent at 500 yards so far. Need to tune on some seating depths and re-test. Heres a pic of the range and a decent N570 group I will work with. You can see the white 500 target in the distance.

 

[Ledd Slinger]

Heres a RL33 load with Rem 9-1/2M primers at 500 yards. Looks to be a little under 2.5" group or so (sub 1/2 MOA).
Pretty decent group, but vertical is bad so I didnt even measure it.

 

[Oso]

There have been a number of studies on impact/performance of different primers. Some are more empirical and others anecdotal.

http://bulletin.accurateshooter.com...tested-for-velocity-essd-group-size-and-more/

This is a great article that someone did their homework and analysis on over a dozen popular primers.

http://www.targetshooter.co.uk/?p=2662

 

[Ledd Slinger]

There have been some studies on impact/performance of sifferent primers.

http://bulletin.accurateshooter.com...tested-for-velocity-essd-group-size-and-more/

This is a great article that someone did their homework and analysis on over a dozen popular primers.

http://www.targetshooter.co.uk/?p=2662

It's great testing, but different primers react differently with different powders. She only tried N140 in one test with LRP's and N150 in the other test with SRP's. With another powder used un either test, those entire lists could be completely flipped upside down, sideways, and inside out. You just never know how a primer will perform in a load combo until you try it.

I would never say one primer is better than the next because they can all work very well in the right combo (except for Winchester, Winchester primers are junk). For some reason Federal primers always seem to ultimately produce the best accuracy for me in the end. Although RL33 and the Rem 9-1/2M outshot N570 with the Fed GM215M at 100 yards, the lead changed when taken to 500 yards where N570 and the GM215M are clearly demonstrating a little better accuracy and a LOT less vertical.

I definitely don't have the extensive inventory in the tests listed above but for what I do have, I have done a lot of primer change tests over the years. The one thing I will say for sure is that theres a good chance the results will surprise you. It's a component in reloading that deserves as much attention and testing in load development as any other part.

 

[JimPag]

I normally use Federal 205's and 205M's in my all of my SR bench 30BR rifles. A friend of mine shot this caliber called a 30 Jaguar, (a modified 30x47 with a radiused shoulder similar to the double radiused Weatherby shoulder) which at the time he had to modify 308 Lapua brass because there was no such thing as a 6.5x47 Lapua case. He did really well with that cartridge earning 3 straight IBS score shooter of the year titles in 2000, 2001, and 2002. Fast forward to around 2010, Sid Goodling took the original Jaguar case and changed a few things that he thought would work better and he called it the 30 Jag II. I ended up having Sid chamber me a barrel for it in 2016 for that upcoming season. Well I started out using a 43.5 dose of N133 with a Federal 205M primer. No matter what I did it would shoot in the 2's and 3's all the time, not good. Made one change to a BR4 primer and bingo, consistent high zero's to low ones. The Federals didn't work worth a shit with that big a dose of 133. Went back and loaded some cases with the Federal's again and same outcome 2's and 3's. Loaded some back up with the BR4's and back to high zero's and low ones. Just goes to show you what one little change can do for your groups. Funny thing is I never had luck with BR4's in my 30BR. The Federal's always made smaller groups with the H4198 or N130 that I use.

 

[Ledd Slinger]

I normally use Federal 205's and 205M's in my all of my SR bench 30BR rifles. A friend of mine shot this caliber called a 30 Jaguar, (a modified 30x47 with a radiused shoulder similar to the double radiused Weatherby shoulder) which at the time he had to modify 308 Lapua brass because there was no such thing as a 6.5x47 Lapua case. He did really well with that cartridge earning 3 straight IBS score shooter of the year titles in 2000, 2001, and 2002. Fast forward to around 2010, Sid Goodling took the original Jaguar case and changed a few things that he thought would work better and he called it the 30 Jag II. I ended up having Sid chamber me a barrel for it in 2016 for that upcoming season. Well I started out using a 43.5 dose of N133 with a Federal 205M primer. No matter what I did it would shoot in the 2's and 3's all the time, not good. Made one change to a BR4 primer and bingo, consistent high zero's to low teens. The Federals didn't work worth a shit with that big a dose of 133. Went back and loaded some cases with the Federal's again and same outcome 2's and 3's. Loaded some back up with the BR4's and back to high zero's and low teens. Just goes to show you what one little change can do for your groups. Funny thing is I never had luck with BR4's in my 30BR. The Federal's always made smaller groups with the H4198 or N130 that I use.

Perfect example Jim. Same type of surprises I have seen with primer changes over the years.

Only difference of course is that I dont have rifles that shoot in the zeros and teens!

 

[dcali]

I’ve never seen anything that dramatic- very interesting. But I also don’t test primers exhaustively. Like you, I tend to stick with one (Federal for me) and can generally make it work. The reason for that is that there are already too many variables to test. Charge weight and seating depths are given. Suppose you test two weights and two depths to get started. That’s four cases. Now add two neck tensions. You’re at 8. Two primers? 16. Two powders? 32. Two bullets? 64. And I don’t know about you, but two of anything hasn’t been good enough to find a good node for me.

So unless you’re shooting the same bullets and powder in the same chamber with the same barrel length in the same rifle barrel after barrel, it just gets out of hand. Primers tend to be the first thing to fall through the cracks. I do wonder if I’m leaving something on the table, but I don’t know how I’d test it well without losing my sanity.

I guess the question is “are primers independent of the other variables?” Your results say that they’re not. This is quite a rabbit hole. I think a lot of shooters may get frustrated when trying to find a node because they’re changing too many things and can’t be systematic about it. They’re basically making random combinations and hoping to find a good one. That’s a very inefficient way to go about it.

 

[jimmymac]

Ttt

I just did a primer change test. I’ve had my 30BR shooting pretty good with Fed 205M’s. I have a load that shoots small. Ran the same seating and powder charge this morning but substituted CCI BR 4’s.

I was surprised by my results. Agged .147 for five, 5 shot groups. Followed that up with 6 groups with Federal primers and agged .227.

I was really happy with the Federals because the gun shoots small. The CCI’s made a difference though.

I get lazy sometimes when my stuff is working. This thread is a good reminder to play around even when you think you have it all together.

 

[Ledd Slinger]

Sped up the N570 load 2 full grains from 90gr to 92gr, then tuned seating depth a little bit.

Heres a 500 yard group with 92gr at 3140 fps and .010" deeper seating depth. Still no vertical and group is a little smaller. Getting there