243 Winchester continued

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Scearcy posted this 2 weeks ago

Someone suggested a few weeks back that I should start a new thread because the first was growing too long.  Fair enough! My initial reaction was that there probably was not much information left that would be interesting. We have had a brief but interesting discussion about the use of H335 the past couple of days in the first thread.

This past month a number of us have been playing with plain base bullets in largely 30 caliber rifles. It was surprising to me how readily we have found pretty good loads using softer alloys and lower velocities. I decided to try the same thing with the 243. My bullet choice is the NOE 105 gr. The alloy is the same alloy I have been using for PB bullets in my 3006. Finally I took a couple of accuracy loads from the older Lyman manuals.

I should mention that I was shooting in a 15 mph gusty wind. So then here is the first group using soft slow fat bullets:

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Scearcy posted this 2 weeks ago

The first group looks like a number I have shot in the past. I think this load would benefit from an additional 1/2 gr of powder.

The next 2 groups are a revelation to me. I only shot them 2 hours ago so in my methodical (slooowwww) way I need to think about this a bit. I thought you guys would find these groups interesting. They are within spitting distance of the National records in Hunter class. Who would have thunk?

45 2.1 posted this 2 weeks ago

A larger sizing diameter and an alloy change (BHN doesn't mean much, it's how you get to it that matters) will get you farther along................

Scearcy posted this 2 weeks ago

45 2.1

I am not sure what your point is? Farther along than what?

Jim

OU812 posted this 2 weeks ago

Scearcy,   I hope you figure out how to do that consistently.

IMR 4198 has worked well for me also...but difficult to meter. Been thinking about buying RCBS's new Chargemaster Lite electronic powder charger.

 

 

...

45 2.1 posted this 2 weeks ago

45 2.1

I am not sure what your point is? Farther along than what?

Jim                      

 

Better accuracy than you're getting now. BHN can be achieved thru alloying certain percentages of antimony, tin, arsenic and lead and air cooled to a certain BHN (or heat treated to a higher BHN than the air cooled produces)....... or a like BHN by using a lot less antimony, tin and arsenic in the alloy and heat treating or water dropping the cast bullet out of the mold.

Example: Linotype air cooled is about 21 BHN and heat treated is a lot more. Most people can find the antimony, tin percentages in lino on the web. A mix of wheel weights / pure lead..... 50% each air cools to about 8 BHN and when it is water dropped it is about 19 BHN after a minimum of two weeks (WW has varying percentages of antimony and tin, but the mix should have about 2% antimony and less than 1/2% tin). Both alloys have close BHN's.. lino air cooled and WW/Pb water dropped. Shoot both in the same load and the WW/Pb will probably shoot better (it has for me).

Scearcy posted this 2 weeks ago

OK I am not really arguing here but rather thinking out loud. First if I can continue to get anything close to the two groups above, it is going to be hard to get me to try another alloy. Second I have 3 pots sitting on my casting bench. One contains pure lino, one contains foundry 92-6-2 and one contains a secret mix (just kidding) that measures exactly BHN 11.5. For the last three months I have shot either pure lino or pure hardball (92-6-2) in these 243s. These are BHN 20-22 and BHN 16-18 respectively. I have shot them slow and I have shot them fast. I have been rewarded with an occasional 1.25&rdquogroup and have shot a bunch of 1.5&rdquo- 2.0&rdquogroups.

There is no magic here but rather well over 800 rounds through 3 rifles using two foundry pure hard alloys and at least a half dozen powders. According to my notes the best groups have usually been in the 1700 fps range using loads which are closer to minimum that maximum. The Lyman manual I have been following notes that best accuracy with the 243 is usually obtained below 1750 fps. That has been my experience also.

I have retired the two faster twist rifles to so they can pursue other interests. Since the slower twist barrel was the most accurate, I decided why not try it with a softer alloy ahead of a slightly gentler load. Why not indeed? If I can get a 7 1/2# sporter to shoot a 9/16&rdquogroup in a 15 mph wind and then follow it with another sub 1&rdquogroup, the load will have my undivided attention.

I have been shooting registered CBA matches for over 20 years. I know that conventional wisdom is that small bore gas checked bullets need to be hard. I have measured some really good groups which were shot using linotype bullets. We compete comfortably in the knowledge that when in doubt, try a harder bullet.

Maybe so, maybe not so. I usually like to believe what my eyes tell me and I have seen very few groups shot with conventional equipment that are any better than that one above. Does one group prove anything? Not much except maybe when it is a tight as the .57 group. Do 2 groups prove anything? Prove - no. Indicate - probably.I believe these are the best 2 groups I have gotten since starting this project. You can be sure I will shoot several more groups before relying heavily on this load but I am unlikely to abandon it before it has been thoroughly tested. I do remain aware of the fact that the warmer weather may be contributing to better performance now. It is also true that I have solved the lube problems I was experiencing early on. Both of these facts could be giving this load an edge relative to the harder alloys I was shooting in February. 

Anyhow this is getting too long. I apologize for sounding irritated but I was. If someone would like to join me in this effort, feel free to say so. PM if you wish. Now that spring is here I will be unable to continue to commit this much time to testing loads.

 

Ken Campbell Iowa posted this 2 weeks ago

thanks jim ... just like watching an old style john wayne movie ... where the hero wins !! ....  good stuff !

do you feel you can comment on your adventures with bullet lube ??

hoping you get a lot more of those amazing targets .

ken

 

 

Scearcy posted this 1 weeks ago

Analysis of IMR 4198 with NOE 105 FN

Load         Average         Extreme          Standard

                  Velocity         Spread             Deviation

13.5 gr      1577                 25                     9.6

14.5 gr      1650                 15                      5.1

15.5 gr      1736                 34                    14.6

16.5 gr      1805                 46                    15.3

17.5 gr      1875                 58                    19.1

None of the loads leaded the barrel. 13.5 gr shot very well on the last trip to the range. It appears likely that best accuracy might be found in the 14-14.5  gr range. 

John Alexander posted this 1 weeks ago

I have been competing  in CBA matches with 223s in factory rifles for over 35 years , sometimes with success against the thirty calibers, sometimes with less.  I am in danger of getting a case of the vapors when I again hear the old saw that you need hard alloys for the small calibers. My experience has been I get luckier when I go from linotype to much softer alloys.

I believe that taking the advice to use hard alloys for the small bores is directly responsible for the belief that the small bores are hard to shoot accurately.

Hang in there Jim and good luck in duplicating those two groups.

John

MarkinEllensburg posted this 1 weeks ago

Thanks for that input John. I think I'll try ww in my .25.

Scearcy posted this 6 days ago

I'll post some more groups in about a week. They will be with the soft alloy.  What I have seen so far makes me a believer but another 30-40 rounds won't hurt anything.

OU812 posted this 6 days ago

I have about 1.5 lbs of“older long&rdquocut IMR 4198.

I read that the newer IMR 4198 is a shorter cut (meters better) and is temperature stable .... much different than the older stuff? I bet it shoots different also. 

Scearcy posted this 6 days ago

My earlier test was with H4198 which is the short kernel temperature stable stuff.  It didn't seem to perform quite as well as the IMR stuff. Its similar but obviously not identical. All I can say is that IMR 4198 looks good in this rifle. I am sure that there are others here who know more about the differences.

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