A Primer on Primers - 24hourcampfire

I've been working with a Stainless Ruger M-77MKII in 300WinMag with a factory 24"Bbl that I replaced the Syth stock with a McMillan A2. Anyhoo, I worked up a pretty decent load with the Hornady 150gr.SP (Moly Coated,Ofcourse),R-P Brass,Fed215M Primer,H-4350 and a OAL of 96.25m/m (Stoney Point Measurement).
 
 I decided to try a few different primers last weekend and got these results;
 
 #1-Fed 215M
 Velocity- 3346,3280,3321,3321,3338
 3-shot group- 0.72", 5-shot group-0.72"
 
 #2- Win.WLR
 Velocity- 3258,3254,3251,3240,3229
 3-shot group-0.68", 5-shot group-1.00"
 
 #3- CCI BR-2
 Velocity- 3238,3254,3270,3256,3233
 3-shot group-0.27", 5-shot group-0.59"
 
 #4-CCI 200
 Velocity-3222,3228,3216,3234,3230
 3-shot group-1.12",5-shot group-2.28"
 
 Amazing what a difference a little thing like a primer will make in accuracy! I plan on testing the CCI BR2 and Fed 215 again this weekend.
 
 I may have to load up on those BR 2 Primers. [Linked Image]

BTW, I don't plan on using these particular bullets for Deer or Hogs but like to work the Bugs out with cheaper bullets and when I feel I have the bedding squared away and have a feel for what the gun likes( OAL),then I switch over to the Higher priced hunting bullets and begin my load development in earnest.
 
 I read alot about how Rugers won't shoot but this particular rifle must not have read the bad press. [Linked Image]

Cheaha. I have done similar things. The following is just my opinion. By changing the primer, you minutely change the velodity or pressure which affects how the bullet leaves the barrel. Some primers are probably made a little better than othersin terms of consistency, but the main factor in accuracy is the repeatability of the bullets as they leave the barrel. Which point in the harmonic mode of the barrel vibration that the barrel is at and repeating it is the criteria
 
 If the bullet leaves at exactly the same point every time , accuracy is superb. Vary that vibration node even a small amount and accuracy drops off. Changing primers, bullets, powder, charge weight of powder, seating depth, all plays a part on finding this sweet spot. This is basically how a Win BOSS works , only you don't have to play around with loads.
 
 When you have an optimun load, go out and buy all the components with then same lot number as fast asyou can.

please post your results, as i am interested in the outcome.
 when i start load development for my rifles, i always start w/ the br-2, and then switch over to federal, and then compare my best loads.
 my best ever groups w/ my 25-06 came w/ federal. best ever groups w/ most of my other rifles comes w/ br-2's. probably because i spend a lot more time developing loads w/ br-2's.
 truth be told, i would probably use federal a lot more if they were easier to get out of the boxes without making a mess.

big time,
 
 Will do.
 
 I've always used Fed 215M in any case that will hold it. I have had good luck over the years with them. I still have about 3 thousand of them in the shop. It is known as a very hot primer so switching primers is relatively safe,as a different primer will usually give lower velocities and pressure.
 
 I tried varying the OAL but didn't see a big change in accuracy so I decided to try a few different primers with this gun.
 
 I will definitly try the BR-2's with the 165gr Hornady SST's that I plan on working up and using on Deer and Wild Hogs.
 
 I use a clean soft funnel shaped paint filter to dump my Federal primers into and then pour them onto my Lee AutoPrime thingy. A coffee filter also works fine. I liked the Old Federal Primer boxes when they were small.

According to the tech at CCI, the only difference between the CCI 200's and the CCI BR's is the higher quality control measures taken in the production of the primers. The recipe, and burn rate, is reportedly exactly the same.
 
 I tested this in my .243 loads which had been using the CCI BR's. I loaded some with the 200's and nothing changed. Point of impact and average group size (.5" at 100 yards) stayed the same.
 
 The CCI BR's are made every other, or perhaps every third weekend. The primer compound spreaders who have the highest degree of consistency in the making of the 200's get to come in on the BR weekend and earn double time wages making the BR's. The workers actually compete with each other for this opportunity, which results in some pretty darned good 200's. If you get a box of 200's which were made by the BR contest winner for the month, you've got essentially the same primers as the BR's. The BR's do, however, have a harder cup. The tech said he wasn't sure why this was.
 
 So, it would appear to me that if your results are that varied with the BR's and the 200's, you may want to test further.
 
 I think I'd try the CCI Magnum primers in your recipe.
 
 Wizard

I re-tested the BR-2's & 215's again this morning with the 150gr Hornadies and got the same results. It appears with this rifle and load,the BR-2's are the way to go. I haven't measured the groups or even got the sand bags out of the Jeep yet but the BR-2, 5 shot group looks to be in the .5's or .6's.
 
 I had planned on working up a good load with the 165gr SST's but may take a look at the 150gr SST's.
 
 
 Wizard,
 
 There appears to be quite a difference in accuracy in this rifle between CCI-200's and BR-2's. I take everything I hear from a "tech" with a grain of salt. [Linked Image]

If they are exactly the same but the BR-2 has a harder cup and he(the tech) has no idea why,then how are they the same? [Linked Image]

Good shooting...James

thanks much for the update.
 
 a friend of mine who has been loading for more years than i've been around told me that generally speaking (realizing each and every rifle can be different), federal is the yardstick he measures by... like i said before, my best groups have come w/ br-2's.

Five shot groups in the .5's and .6's from a sporter barreled Ruger 300 Win. Mag. without sandbags?
 
 That's definitely good shooting!
 
 Wizard

Wizard,
 
 You and your "Tech" friend might do load development without sand bags but I don't. What I said,was I hadn't measured the groups or even got the sand bags,chrono,etc out of my jeep after I got home,so I didn't have exact measurements to share. I hope that's not to hard for you to understand. Perhaps you could get your "tech" friend to explain things to you. [Linked Image]

I didn't mean to ruffle your feathers. My original intent was to provide some information which I thought would be helpful to you.
 
 Sorry about misunderstanding your post.
 
 I come away from this understanding that I'm to take what a factory tech says with a grain of salt, and what you say as gospel. Is that what you're asking?
 
 Wizard

Wizard,
 
 All I'm saying is we should try things ourself and not automatically take the word of a tech or anyone else. Sorry If I came across as a smartazz.
 
 Do you own a chronograph? I thought for years I was really screaming with my 7 mag loads. I finally bought a Chrony and discovered my actual velocity didn't come close to "Book" velocities. I decided I would only use other load data as a guide and not take book data or tech talk as the gospel. That's all I'm saying. Have a good day...James

I do see your point, and concede. It is true that factory techs are sometimes not as informed as they should be.
 
 I've been thinking about it and it is possible that the harder primer cups could change lock/ignition time just enough to make the difference. One of my mottos is "Don't argue with what works."
 
 Congratulations on the ownership of a great shooting rifle.
 
 Take care,
 
 Wizard

Please don't mind if I butt in but, Sometimes the factory techs are production techs...they know about making widgets not necessarliy what the end user uses it for...
 
 Mike

You're right, of course. I think for the most part the techs are pretty knowledgeable, but I've noted exceptions.
 
 You'll get all kinds of load data discrepencies, for instance. Sierra likes to draw the line fairly early, and the powder manufacturers allow much stouter charges.
 
 I once asked a Burris tech for some advice on the operation of a scope, and he said he'd have to get back to me. As I learned more about the operation of riflescopes, it became apparent to me that the Burris tech should have known the answer to my question without checking any greater sources.
 
 Another time, a few years ago, I contacted a purported tech at Tasco and told them I was having zero problems with my scope. His response? "Well if you're having zero problems, why are you calling customer service?" [Linked Image]

Leupold techs are great in my experience, as are Sierra, Hornady, and Hodgdon techs.
 
 Back on the thread, I tested what the CCI tech told me in a couple of my own loads, and it seemed to be good information. Cheaha's experience shows that the two primers aren't necessarily interchangeable for every application.
 
 Wizard