Primers: how much difference do they make?

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I'm running out of federal 210's, and about to work up new loads to possibly switch from the 168smk to the 175smk or vld.

I understand that certain things only begin to make a difference once you get to that level. So far i've been getting my rifle to shoot .5 when I do my part, .75 on average when making mistakes, and the best so far was .33. I'm not sure where that puts me, and not sure what little factors are starting to become relevant.

So, what could I gain from switching to BR2's or fed 215's, or something else? I know they are more expensive and harder to find, but could I see a worthwhile gain in consistency? Are they also more consistent over temperature extremes?

What do you use?

Thanks!

(posted in "precision rifles" instead of "reloading" due to specific application)

.....off to go shooting in the "blizzard"....fun!
 
i once had a rem700 in 300wm. my load was 79g rl22 over was a 165g ballistic tip. not having any magnum primers i used standard winchester large rifle. this load shot beautifully out a stock untouched rifle with almost 3300fps and 3" groups at 300yds. upon reloading i had restocked my primer supply with winchester large rifle magnums. i also changed out the bullet for Hornady 165g interbonds. accuracy went to hell and i was getting sticky bolt lift, so i chronographed this load and wow! 3495fps!!! i am not sure if it was the primer or the harder bullet, but i backed off the powder charge by two grains and evreything returned to normal. i dont know if this is a good example but i think it has less effect on a large capacity case compared to a smaller capacity.
 
snoopycda said:
i once had a rem700 in 300wm. my load was 79g rl22 over was a 165g ballistic tip. not having any magnum primers i used standard winchester large rifle. this load shot beautifully out a stock untouched rifle with almost 3300fps and 3" groups at 300yds. upon reloading i had restocked my primer supply with winchester large rifle magnums. i also changed out the bullet for Hornady 165g interbonds. accuracy went to hell and i was getting sticky bolt lift, so i chronographed this load and wow! 3495fps!!! i am not sure if it was the primer or the harder bullet, but i backed off the powder charge by two grains and evreything returned to normal. i dont know if this is a good example but i think it has less effect on a large capacity case compared to a smaller capacity.
Click to expand...

First mistake was to change 2 components at one time. If you have to switch primers,bullets, cases then you should change only one at a time.

The BR2's are very good primers and a lot of competitive shooters use them in their match loads.

I use the BR2's in my 260 Rem and 284 Shehane.
 
Primer lots and brands will make little to big differences. My old .260 AI shot better with lower SD and standard Fed 210. The match primers gave bigger SD. Finding Fed primers in LR is getting tougher so I'm now testing Win LR, CCI LR and will get some BR2 and see what gives me the lowest SD.
I always use the primer that gives me the lowest SD then find the powder that gives me the highest velocity, lowest SD combined especially for long range.

I have stacks of testing I did years ago with chronograph and different cartridges to bear this out. The chronograph is a good investment.
 
I did some experimenting last season, here's what I found;

The load I've been using in my .223 for F Class out to 900m has been Berger 90 VLDs, with H4350 and CCI 400 primers. It's consistently accurate and as far as I'm concerned the limiting factor is me not the equipment. I've chronographed this load and it's consistently around 2740 - 2750 fps. It will usually do a .25 MOA group at 100 Yards.

I took this load and loaded 6 rounds each with CCI 400, CCI BR4, Fed 205M and Remington 7 1/2 (BR) primers. I shot each load as two groups of three. I weighed the charges with a Jennings Mack20 which is supposed to be accurate to .02 of a grain, and I tried to keep all charges within .02 of a grain. Seating was with 20 thou jump to the lands, and I checked all seating with a comparitor to be within 1 thou of the desired setting. The cases were once fired Winchester from the same lot, neck sized with a Lee collet die.

- The group size was virtually identical with the CCI 400, CCI BR4 and Fed 205M primers.
- The velocity was virtually unchanged (2745) between the CCI 400 and the CCI BR4 primers, but the extreme spread was 15 fps with the CCI 400 and 8 with the CCI BR4
- The extreme spread was even better (5 fps) with the Fed 205M, but the velocity was lower, around 2725
- The worst extreme spread (around 45 fps) and the worst accuracy was with the Remington 7 1/2 primers.

Sorry, I only did this once with ambient temp around 15C, so I can't say what may change with increased/decreased temperatures. Mysticplayer told me that the CCI 400s ignite better/hotter in cold weather than the CCI BR4s, and when Jerry says something I've found it's always been because he's proven it himself.

Hope this helps
 
You may find this article of interest.

Large Rifle Primer Test

I did some analysis of other data and found CCI primers tend to be the least affected by temperature.
 
mmilne, it was the CCI 450. The 400's are the reg version of the BR4's which are supposed to be manf to better tolerances/consistency. The 450's work way better in the cold especially if you use ball powder.

Primers can make a huge difference in your load tuning especially at long range. They also have different cup thicknesses which flatten at different rates.

I used CCI BR2 for all my match shooting when a LR was called for. Earlier in my shooting career, I saw substantial group shrinkage at LR when using this primer vs reg. primers. I never bothered testing as I went along as I didn't care for the few extra pennies to take any chances on performance.

I have used Fed 210M and 215M alot too. 215M is my goto primer for big honking cases. Shot my smallest 1000m group with this primer.

With my 223's, I found the CCI 450's worked just as accurately as the BR4's but were less sensitive to cold especially when using any type of ball powder. I now use the 450's for everything so I only need to keep 1 SR primer onhand.

Cup is tough enough to be used in semi's too which is nice.

Wolf LR is another great primer but not easy to get.

Match primers can help. They certainly will not hurt. Reg primers can do a great job and the only way to know is test.

At 200 and 300yds, you will see small changes in your load tuning especially the group orientation.

When I switched to BR2's, the group size shrank by 50% at 200yds mostly because the occasional high and low shots were eliminated.

For competition, it only takes one out to ruin your day. for smoking rocks or gophers, just send another.

The goal is to use the primer with the least amount of flash that can reliably ignite your powder charge. Using an overly hot primer can increase pressures ALOT without changing your velocity - illustrated in a Handloader article from several years back

The BR2 and Fed 210M are two of the mildest LR primers and very consistent. The BR2 cup is substantially tougher then the 210M's.

Jerry
 
You can find some primer dimensional data at this link. There is some variation in cup metal thickness in the small rifle, but not in the large rife. Also, I would not put too much faith in the diameter and height numbers in the chart. They have not matched measurements I've taken with recent lots of primers.
 
That's some great info!

So far, it looks like i'll switch to the BR2's. I had a few misconceptions about these before, debunked by this thread.

The only thing I wonder about them, is if they would have the same difference in temperature consistency as the BR4/450 comparison. Do you think they would be at least as consistent in the cold as the 210's?

Accuracy comes first, of course, but I would like to work up a good all-around long distance load and mostly stick with it, so that I can record real-world data with it under a lot of varying conditions. When I shoot up north, I love the challenge of getting first-round hits at varying distances, instead of walking rounds in with sighters. Minimizing the effects on the muzzle velocity when shooting between temps of -20 and +30 would really help!

What I have so far:
-.308, 24" barrel, 1:10 twist

-Win cases, mostly just neck-sized. I run them through the body die in my redding set if they get hard to chamber.

-175 SMK's, Will also work up a load for 175 VLD's after, to see what it likes more. Have been using 168's up until now, the switch comes after some messing around with JBM calculators, seeing the flattest trajectories. Perhaps the longer bearing surface on the 175 SMK might match up well with my fast twist, too?
(note: playing around with the 175 SMK for the first time, I shot my best group ever of .33, all the rest of the "proper shooting technique" groups were under .5 moa. Nothing spectacular for the really experienced shooters here, but very spectacular for me!)

-Varget. Chosen as the starting point due to its reputation for consistency under temperature variations. I "think" there is a node between 44.6 and 45.0 grains with 175 SMK's. 45.0 got me 2730fps. This was with Fed 210 primers. Will explore further with a ladder test using BR2's when I can get to a longer range in the next few weeks, I only have 100yds to work with right now.

-2.806 OAL, gets it about .010 from the lands. Haven't messed with it yet, until I get the rest figured out- I figure ten thou was a reasonable starting point. Have noticed more consistent OAL's when using VLD's and Scenars. Am considering purchasing one of those comparators that measure from the ogive to see if I can get more consistent distances from the lands from batch to batch.

Do you think the BR2's would be ideal for that load?

Any other suggestions?

Thanks again, for the massive amount of help! I sincerely appreciate it!
 
BR2 will work in pretty much any temp you might want to target shoot in.

Visit my website and look in the Tech section - Reloading for some articles on how to tune your rifle.

It is quick and works.

I assume that you have a factory rifle???? If so, 1/2 min AVERAGE is plenty good in my books.

Jerry
 
Thanks Jerry, that's where I learned about the ladder test. I will definitely read the rest of your articles, very good stuff!

Rifle is a Savage 10FLP I bought last summer, and bedded into a McMillan A5 with vBull bottom metal. It has a factory barrel, about 550 rounds through it so far. It's my first precision rifle after 10 years of wanting one/not being able to afford one, and I'm having a great time with it now.
 
Mystic Precision said:
If so, 1/2 min AVERAGE is plenty good in my books.
Click to expand...

Thanks, but it's only if I do my part. Real average is .7 because of a stupid, frustrating, STUPID error I seem to make every other group or so. Diagonal stringing toward the weak side. I think it has to do with trigger control, it's totally visible when dryfiring. I've been working really hard to get it figured out.
 
I used the data at this link to compare large rifle primer effect on loss of velocity due to cold temperatures. I looked at the average velocity loss of all the powders combined, but sorted by primer type. So the velocity loss is a combination of the powder loss and primer loss. But since the powders stayed the same for all primers, I believe the difference in loss was due to the primer. Here are the losses from best (least) to worst (most loss):

BR-2 - 2.58%
CCI 250 - 2.66%
WLR - 2.75%
210M - 3.04%
215 - 3.08%
WLRM - 3.11%
RWS - 3.37%

The differences are not huge, but remember that most of the loss is due to powder, while the differentials are due to primers. It is interesting in that it shows there is no advantage to magnum primers. They seem to lose more velocity than the standard versions. Also with the exception of Winchester the regular and magnum seem to behave very similar with respect to temperature.

Hope that helps some,
 
RonAKA, according to a Handloader article, pressure testing has shown there is not a good correlation between pressure and velocity with respect to primers.

They showed that a magnum primer does increase chamber pressure significantly even though velocity didn't change or changed very little.

From tests you quoted, did they indicate what the orig velocity was and what the error on their chronie was? A higher % loss from a higher start velocity may still yield higher velocity AND pressures.

And if the error in the chronie reading is significant, then the value of these calculations is suspect. Electronics don't like cold too....

Best way is still to use what you can find, and what gives you the consistency/accuracy you want.

Jerry
 
Mystic Precision said:
Shooting with a bipod?

Or pedestal rest and properly fitting bag?

Jerry
Click to expand...

Lately shooting off a bench most of the time, resting on a pile of sandbags. Shooting prone with a bipod too. I believe I make the mistake in both positions, but I will have to double check to be 100% sure.

When I get to shoot up north in the summer, it is 95% prone from a bipod.
 
Jerry, the only information I have is what is contained in the link. As always I would assume chronograph error is significant. But I think they shot enough loads that error should have been consistent and nulled out due to the use of the same instrument for cold and warm testing. And, from what I read in the article they were not comparing cold weather to warm weather, just warm cartridges (powder) to cold ones they had in the freezer over night. So the chronograph would not have been exposed to the cold.

With the exception of the Winchester primers, the consistency of the magnum to standard would suggest to me the test was reasonably valid, and also that again with the same Winchester exception, the difference between magnum and standard is probably not the type of primer compound, but just the quantity.

Also, I was not checking for performance of magnum to standard with respect to velocity. I only compared Magnum warm to Magnum cold, and Standard Warm to Standard cold. I'm sure the Magnum velocities were higher, but I was only looking at loss due to temperature on a percentage basis.

One possible expalaination might be that primer compound may be much more temperature sensitive than powder. So in a load that has a magnum primer, the energy contribution of the primer is higher on a relative basis. Then, when the temperature drops the load with more primer material suffers more than the one with less. Just a guess...
 
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