SRP much difference?

[KMW 1954]

When I first started loading small rifle it was a Savage 10 in 223 and it shot well with CCI400 primers and I have 300+ left of those. Then I moved to a Savage 11 223 that right away started cratering those 400 so I switched to 450's and that cleared it up. Then the primer shortage and I couldn't source many 450's but found a steady supply of Remington 7 1/2 so I started using those.

Now I am loading a Savage 110 6mmARC and having just started I don't really have a load yet. So I tried the CCI400 in it and they shot well and didn't see any signs of crater. So I am thinking of using these up before going back to the Remington. So I guess my question is does anyone see any real world change in accuracy between general primer selection? So we are all clear I understand there will need to be adjustments made when changing components.

 

[RegionRat]

So I guess my question is does anyone see any real world change in accuracy between general primer selection? So we are all clear I understand there will need to be adjustments made when changing components.

If you stay with this topic for very long, you will find that primer changes can do both, they can make a huge difference in one context and make no difference in another. So, once again, you get an "it depends" answer, but your basic answer is yes primers can make a difference in both group performance, point of impact, reliability, or combinations of these issues.

To find out if your context is one where it matters or it doesn't, there is only one way to know and that is to go try.

All of the primers you named are good to be familiar with and good to keep some on hand.

When you like a type of primer, try to stock up to avoid batch to batch issues or shortages.

Primers by and large are still made by human hands, and while they are very reliable there can be variations within a batch as well as between batches. Sometimes, there are even quality escapes.

As a hobby consumer, you will have to pay attention to places where there are known pitfalls such as combinations that cause trouble. An example of combinations that can cause trouble are hang-fires with ball powders + mild primers in very cold weather. If you are starting out, try to stick with known recipes and be prepared for shortages when possible.

 

[CJ6]

The cratering is most likely from excess firing pin clearance.

 

[bozo699]

If you stay with this topic for very long, you will find that primer changes can do both, they can make a huge difference in one context and make no difference in another. So, once again, you get an "it depends" answer, but your basic answer is yes primers can make a difference in both group performance, point of impact, reliability, or combinations of these issues.

To find out if your context is one where it matters or it doesn't, there is only one way to know and that is to go try.

All of the primers you named are good to be familiar with and good to keep some on hand.

When you like a type of primer, try to stock up to avoid batch to batch issues or shortages.

Primers by and large are still made by human hands, and while they are very reliable there can be variations within a batch as well as between batches. Sometimes, there are even quality escapes.

As a hobby consumer, you will have to pay attention to places where there are known pitfalls such as combinations that cause trouble. An example of combinations that can cause trouble are hang-fires with ball powders + mild primers in very cold weather. If you are starting out, try to stick with known recipes and be prepared for shortages when possible.

Very well stated!….
Wayne

 

[JFrank]

From what I’ve seen, 100 yard primer testing results will have very subtle differences between brands and offerings within a brand name. A person needs a very accurate, steady platform and test during ideal conditions or with wind flags or shoot longer range round robin ladders or a variant style format to have a primer stand out. For non br 100 to 200 yard shooting a fella could pick a primer that can handle a bit of pressure and build a load around it just as easy.

 

[KMW 1954]

If you stay with this topic for very long, you will find that primer changes can do both, they can make a huge difference in one context and make no difference in another. So, once again, you get an "it depends" answer, but your basic answer is yes primers can make a difference in both group performance, point of impact, reliability, or combinations of these issues.

I can live with the "it depends" answer as I stated any change can make a difference. Like powders, bullets and primers yet my limited experience to me shows very little difference in use of primers and overall accuracy when compared to the other two components.

So let's put it this way. I am at best a 1/2 MOA shooter. Yes at times I can put together a group much tighter than that but on average I am right around .5+ MOA. So is primer selection so sensitive that a shooter such as myself will really see a difference? I know a few I do shoot with would but I am not there yet.

Sadly at times budget dictates what we can afford to purchase and the quantities allowed.

 

[KMW 1954]

The cratering is most likely from excess firing pin clearance.

Reason I changed the primers and not the load.

 

[RegionRat]

So let's put it this way. I am at best a 1/2 MOA shooter. Yes at times I can put together a group much tighter than that but on average I am right around .5+ MOA. So is primer selection so sensitive that a shooter such as myself will really see a difference? I know a few I do shoot with would but I am not there yet.

Sadly at times budget dictates what we can afford to purchase and the quantities allowed.

Yes. But, you can't be budget shy about collecting some primers to test. Do this a little longer, and you will see the difference between primers, and then even within a primer batch change. It takes work.

Anyone who can truly shoot 0.5 MOA on average, is well ahead of two thirds of all shooters. When they can do this under pressure on demand, they take podiums at matches. If that is you, don't sell yourself short.

It takes some doing to master good loading and load development, but you could hand a good beginner the tools and recipes and they could produce good ammo.

What beginners can't do is shoot in wind, or develop good loads. We spend a fair amount on juniors and rookies while bringing them up to Master and Distinguished, but we can do that without them ever learning internal ballistics.

Like I said earlier, don't sell yourself short if you are a 0.5 MOA shooter. Go visit the types of matches you are interested in, even if you never plan to compete. You will see if they think primers make any difference and see what their shooting looks like first hand. YMMV

 

[RegionRat]

Reason I changed the primers and not the load.

Two more pieces of free advice you didn't ask for...

Think about bushing the firing pin hole on that rig, but....
Be careful to learn to anticipate pressure and don't flirt with high pressure till you know what you are doing.
It is possible to have a good rig mask signs of high pressure, so play it safe and worship at the alter of accuracy and wind, not at the alter of pushing pressure.

 

[KMW 1954]

Two more pieces of free advice you didn't ask for...

Think about bushing the firing pin hole on that rig, but....
Be careful to learn to anticipate pressure and don't flirt with high pressure till you know what you are doing.
It is possible to have a good rig mask signs of high pressure, so play it safe and worship at the alter of accuracy and wind, not at the alter of pushing pressure.

Yeup, on this one the bolt head definitely needs work. Have talked with Desh a while ago and now I see he is having some health issues. My other 223 shoots those loads just fine.

Have been competing the past 3 winters in a local informal bench type league with these 223. I can keep up at 100 and 200yds. At 300 yards I start falling off and yes some is wind some is the operator.

 

[jelenko]

right around .5+ MOA. So is primer selection so sensitive that a shooter such as myself will really see a difference?

As JFrank mentioned, at .5 MOA it is difficult to see the difference in primers with everything else the same.
But, if you're competing in benchrest comp, I'd suggest you stay with the same primer as much as possible.
If/when you do have to change, I'd do a refresh on my powder charge looking at just above and below the charge you've been using.
You really don't want the ammo to shoot worse than you. My understanding is .5 MOA is close to where the differences in primers will show up.

 

[Laurie]

Smaller cartridges are often very primer sensitive indeed, and there are many references from the professionals to this as well as recreational shooters' often more subjective findings.

Bryan Litz found this as a side-issue in carrying out testing on a different subject (Modern Advancements in Long Range Shooting Vol II) in this case affecting large cartridges such as the .300 Win Mag. Bryan measured results in terms of MV SD size, and some primer models simply wouldn't give small SDs in the combination used as a test bed.

Bill Alexander finished off a list of 6.5mm Grendel 'pet loads' for those new to the cartridge with advice that having found an apparently promising combination to then try every primer you could lay hands on as this cartridge is very 'primer sensitive'. Not a great help right now of course with primer shortages and vast price increases!

I found substantial group size changes in a 223 Rem test load where everything other than primer model remained constant. This was in a very heavy barrel F-Class rifle built on a Savage 12 PTA action capable of quarter-MOA or better groups off the bench at 100 yards. TBH, although I've long known about such sensitivity, I was very surprised by the degree of change in group size over four primer models. However, when we work up a load with a singe primer, we 'tune' that load for one primer model and need to redo the fine-tuning after a primer change, so one model may be neither better nor worse than another overall, just different. (That of course invokes the reverse side that one shouldn't change primer model in a satisfactory load without a retest, and certainly never, ever, change primer make/model mid batch / mid competition for applications needing a high level of precision.)

 

[quest450]

I always start tuning my new 6BRA barrel with combination of H4895/BR4/Wheeler 103's 8thou in the lands, after the new barrel tells me what powder charge, seating depth, neck tension it likes I run a quick primer test BR4's vs 450's and go with not necessarily smallest but more consistent, round group with the least vertical, since I did load development with BR4's I sometimes wonder if load development should be repeated with the other choice of primers or at least tweaked a little bit to squeeze the most accuracy

 

[KMW 1954]

TBH, although I've long known about such sensitivity, I was very surprised by the degree of change in group size over four primer models. However, when we work up a load with a singe primer, we 'tune' that load for one primer model and need to redo the fine-tuning after a primer change, so one model may be neither better nor worse than another overall, just different.

This is more or less what my questioning is. Can the change usually be tuned to give similar results or No.

Yes I have also read the articles that even primer seating can have an effect.

Also in my first post there is a typo. I actually have 3k+ of the CCI 400 primers on the shelf and would like to use them up seeing as I cannot use them in my 223.

 

[Laurie]

This is more or less what my questioning is. Can the change usually be tuned to give similar results or No.

IME, sometimes but not always. Obviously, the number of possible permutations of primer, powder grade, and charge weights is such that you'd wear the barrel out long before answering that question.

When you find something that works in your rifle, the cartridge, and chosen powder grade, then stick with that combination, refining it best you can. If you have 3,000 CCI-400s and they're working well in the ARC in your Savage and you're not getting cratering (the 400's 20 thou' thick cup's bugbear), then what's not to like?

However, because something works for you now in that rifle, it may or may not behave identically in another and/or new barrel even from the same maker.

@quest450 's post above is what most of us do. Maybe not perfect, but life (and barrel life) is too short to seek perfection in this regard (possibly with the exception of a handful of top BR competitors).

 

[KMW 1954]

Thank you Laurie, once again looks like I'm making a bigger pile than necessary.

Seeing as I am just starting this adventure and after seeing these work in this rifle I will proceed and use them up and just be happy I have primers.

Thanks all for the feedback and in-sight!

 

[Straightshooter1]

When I first started loading small rifle it was a Savage 10 in 223 and it shot well with CCI400 primers and I have 300+ left of those. Then I moved to a Savage 11 223 that right away started cratering those 400 so I switched to 450's and that cleared it up. Then the primer shortage and I couldn't source many 450's but found a steady supply of Remington 7 1/2 so I started using those.

Now I am loading a Savage 110 6mmARC and having just started I don't really have a load yet. So I tried the CCI400 in it and they shot well and didn't see any signs of crater. So I am thinking of using these up before going back to the Remington. So I guess my question is does anyone see any real world change in accuracy between general primer selection? So we are all clear I understand there will need to be adjustments made when changing components.

I've found primer selection can make a difference, sometimes a very small difference and sometimes a large difference. I certainly get a difference in my .308 SRP Lapua brass going from CCI-400's to CCI-450's. But not much between CCI-400's and Federal 205's, if any. And going from a LRP to SRP case has shown a difference for me out of my .308. Going with the SRP's I get more consistent results.

Back in January, I bought some Remington 9.5's with the idea to simply use them for fire forming some brass. As I do enjoy experimenting to see what does or doesn't work, I loaded 45 cartridges up last week with my favorite load for 169 SMK's in used well prepped cases, but using these Remington LRP's. I wanted to see what kind of difference I might observe. I made sure to seat the primers to touching and of the 45 only 3 were difficult to get the same distance below the base. Well, it was actually shocking to me. I got the worst results I could have possibly imagined. Velocity ES was 87 fps, about double what I normally see and an SD of 20.4 (more than double what I usually get). Average velocity was ~40 fps higher than normal (normal being ~2740 fps). What I was observing on paper was interesting in that for the velocities around 2760 - 2775, the groupings for them were tight. About 1/3 of all the velocities were over 2800 fps and in the 5 shot groups they showed distinct POI shifts, like what one might call flyers, especially the highest one's that also exhibited a little stiff bolt lift. With all the different combinations I've played with (bullets, powders, cases, primers), I've not had this dramatic difference. I was expecting some difference, but wasn't expecting this. . . . especially the inconsistency.

If anything, this shows me, in quite a dramatic way, that primers can make a difference. Also, a couple weeks ago, on some new Alpha .308 brass out of the 10 cases using CCI-400's I got 3 pierced primers and will now try the CCI-450's as they should stand up and not get pierced (we'll see on my next outing).