My 17 and 20-.223 Improved load development experience

platapus

platapus

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I've had a few .204s, which started my admiration of the small calibers. My favorite was an AR with a Shilen barrel I built to shoot the the 50gr Berger. I sold that rifle with 1k of the Bergers, I kick myself.

On a side note, the only folks to make decent coyote bullets for the 17 and 20 any more are custom bullet makers. Please support them.

IMO, I think the 20 cal with the right bullet is the best bang for your buck for a coyote caliber. Fast,flat, excellent BC, excellent barrel life, and minimal if any pelt damage.

I do not use polymer tipped bullets period for coyotes, to many mixed results. I'm not saying you can't or shouldn't but I won't.

Fast forward and I built a 223 40° Improved in an AR with a Hart barrel shooting the 68gr Hornaday HPBT. Rifle shoots fine but I guess I just never really fell in love with it like the 204.

I have 400ish rounds loaded with the 68gr and when they're shot up, this rifle will get a 20 cal barrel. Yeah, you guessed it, a 20-223 Improved.

The 40° Improved design, you just don't have to trim. Big plus even though I have the equipment to do it.

Being I bought Redding Type S bushing dies, I decided to build a 20-223 Improved. This time in a bolt gun with a steel Proof barrel.

Why go this route over a 204 you might ask? I am not a fan of Hornaday brass whatsoever. This is based on my experience only, in several calibers. Yeah, I know that there are other 204 brass manufacturers but not Lapua. 223 Lapua brass necked down is as consistent as it gets and will last forever. Well not forever but 15+ reloadings with annealing is as good as it gets.

Benchmark is my go to powder for the 20 cal. I learned this testing different powders with my first few 204s. It just works. Other powders tested were Varget, H322, and Ram Shot Big Game.

Fire forming load is 24.5 gr Benchmark shooting the 39gr SBK. Shot half moa right off the bat, consistently. I fire formed 200 rounds and started load development with the 39gr SBK for pd's, and the 40gr BiB for coyotes.

*Disclaimer*- charge weights listed are for MY rifle! Do your own workup! I am sharing this because there just wasn't this type of data out there for me and hope it will help someone with similar setups. I did reach out to several folks I found who were great in sharing data.

Both bullets were tested 24.7gr-26.5gr Benchmark in .2gr increments, 3 rounds each and shot over a Magneto Speed 3 chronograph. I didn't see any pressure signs. Primers all looked good and no bolt swipes.

39gr SBK

24.7 3531 3554 3559 SD- 14.9 ES- 58
24.9 3554 3576 3561 SD- 16 ES- 32
25.1 3649 3523 3638 SD- 13 ES- 26 Chose this one obviously
25.3 3654 3623 3623 SD- 17.8 ES- 31 Close second
25.5 3720 3703 3654 SD- 34.2 ES- 41
25.7 3703 3753 3687 SD- 34.4 ES- 55
25.9 3736 3787 3720 SD- 35 ES- 67
26.1 3822 3822 3736 SD- 49.6 ES- 86
26.3 3858 3787 3822 SD- 35.4 ES- 71
26.5 3858 3805 3858 SD- 30.5 ES- 53

40gr BiB

24.7 3502 3427 3478 SD- 38.3 ES- 75
24.9 3470 3442 3506 SD- 32 ES- 64
25,1 3520 3481 3546 SD- 32.7 ES- 65
25.3 3601 3551 3509 SD- 46 ES- 92
25.5 3553 3608 3605 SD- 30.9 ES- 55
25.7 3652 3635 3611 SD- 20.6 ES- 41
25.9 3702 3608 3651 SD- 26.2 ES- 49
26.1 3702 3689 3679 SD- 11.5 ES- 23. Chose this one obviously
26.3 3679 3663 3703 SD- 20.1 ES- 40
26.5 3682 3757 3748 SD- 40.9 ES- 75

Notice there is a full grain difference between the two bullets. It's all harmonics.

I haven't made it back out to complete the seating depth test. It will go as follows and I will update the thread with the results.

39gr SBK- 1.927-1.900 BTO 3 rounds each in .003 increments at 250 yards or so.


Now for the 17-223 Improved.

I had an Plum Crazy Lower sitting for 10 years that needed used. I found a Lija AR barrel here and picked it it. Easy once again being I had the Redding bushing dies. I gathered the rest of the parts needed and threw it together.

My plan for this one was as light as I could build it shoot a 30gr bullet. I know the 17s are super finicky to load for and did a lot of research on powders. I should have just trusted my gut and went with Benchmark as I'll explain.

I used once fired LC brass sorted by weight and sized them down. 6 steps I belive. It was tedious but I don't mind.

Fire formed with 25gr Hornaday Vmax with 24gr Benchmark. Load shot at moa, nothing special but I wasn't concerned, just wanted them formed.

I originally went with Ram Shot Big Game shooting the Nagle 30gr. 25.5gr-27.7gr in half gr increments. The 27.7 load is what I initially went with but determined I was just in the pressure curve so backed off to 26.6 with an average speed of 3727 fps. Load shot right at moa. I threw out the load development data on the Big Game or I would have posted it. Nothing real consistent or to write home about. High SD's and even higher ES's.

On a whim, I decided to do a charge weight test with Benchmark, man am I glad I did.

I did the exact same charge weights as with the 20-223. 24.7gr-26.5gr, 3 loads each.

30 gr Nagel

24.7 3944 4025 3987 SD- 40.5 ES- 81
24.9 4006 4006 4006 SD- 0 ES- 0 WHAT!!!
25.3 4055 4077

And that is where I stopped. I had a failure to feed on the 3 shot of 25.3 and the bullet stuck in the barrel, powder everywhere. Hate that.

Still have to do the seating depth test with these. I loaded them at 1.937 BTO or 2.25 oal for mag length but obviously a little long if I stuck one in the barrel. I will back off .020 and test 1.953-1.928 BTO in .003 increments.

I can't figure out how to post pictures here or I would, most difficult of any site I frequent.

I hope this helps someone and would be happy to answer any questions.

 
A lot of good info there. Thanks for sharing the load data.

My .20 caliber is an .204 with an X-Calber barrel. This is the third barrel I put on it as it works so very well on our local ground squirrels and prairie dogs. The 39 grain Blitzkings will flat out launch a prairie dog into orbit. A friend just recently built a .20 Practical and it is every bit the shooter my .204 is. The .20/223 AI would be even better yet I think.

I have owned .17 Remingtons for 40 years now and am fond indeed of the round. But if starting over today I think I would go for a .17/223 or a .17/204 instead. Years ago I had no problem at all finding .17 Rem brass and if you bought in bulk was almost a bargain. I have enough to last me the rest of my life I'm pretty sure.

Yes, those 30 grain Nagels are superb. The only thing that I have shot with mine so far was a big fat rock chuck. One shot was plenty a he was dead where he was hit. Will be taking it out again for that.
 
Thanks Rustydust. I've only shot one coyote with 17 Remington. It was last Thanksgiving. My uncles rifle who's had it since I was a kid. 25gr hp, dirt. It was then that I knew I wanted to build one.

One thing I didn't mention was in my experience, obtaining singal digit SD's with the small calibers is not an easy thing to achieve as with larger calibers.

Needless to say, pretty excited about that load. Ran some quick numbers 1 inch drop at 300, 2' at 366, 3" at 422. That's flat!
 
My .17 Rem is an X-Caliber. They no longer make .17 barrels though. When I called to ask why I was told that it is too hard to make them perfect and they will not let a less than perfect barrel out of their shop. They had to scrap too many barrels for every good one so it was unprofitable for them to sell them. Guess I got lucky.

Anyway, mine is a 26" 1/10" twist and it bugholes those Nagel bullets. Chan will only sell two boxes of them at a time but after seeing how they shoot I will cherish what I have until I can get more. I might have to take a few prairie dogs with them next spring however. According to your drop figures (thank you for that) they ought to work just fine at this task.
 
xbr8208, try it, you'll like it. Hopefully. My recently completed AR15 upper with the X-caliber 204 Ruger barrel is wonderful. It likes most powders I tried in it.
 
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Great write up and information.
IMR8208 is my choice for the 17Rem and the 204.
30gr. 17 cal. bullets I use H414. Win. 760 is the same powder.
 
With the 17's and 20's I don't worry about velocity deviation, mainly because hunting shots are typically under 300 yards. I have a couple rifles that would shoot the 2 gr powder range into 1 moa. Find the best load on targets then test it in the wind at 200. Yes the group will be out of the bullseye, but should still group well. Then you know powder charge and seating depth is "tuned". I run H414 in my 17 rem with 29-30's, shoots very well on targets and in the cold winter wind(which is all that matters from my fur rifles).
 
I finally made it out, wind has been ripping here and there was a window just before dusk.

I shot the .20-223 Improved at 267 yards, 3 round groups.

39gr SBK- best seating 1.906 BTO shot a .891 group
40gr BiB- best seating 1.871 BTO shot a 1.138 group

Very pleased with these.

Basically found a load for each bullet in 60 rounds.

I ran out of daylight for the .17 but am going out Thursday and will update.
 
Went out this morning with the. 17-223Imp to completed the seating depth test. At 268 yards, seating 1.935 3 shot group 1.018.
 
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