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.223 rem new build


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Hi all,

 

I'm building a new .223 rem target rifle for prone NRA type competition in Scotland (.223 rem being allowed alongside .308 win in competition) and I'm looking for advice on bullet choice. I have a 32" 1:6.5 Palma profile Krieger to fit (I might chop down to 30") and will mate it to a Grunig action with reworked boltface and extractor. Geoffrey Kolbe is making me a reamer with a .252" neck and I'll use this with non turned Lapua Match brass. I have 500 of the newer high BC Sierra 90g bullets which I won at the Hopton meeting but keep hearing reports they're not as good as the 90g Berger equivalent. Is this indeed true? My research suggests the 90g Sierra is of a new design (replacing a previous part number) and on paper now has a higher BC than the Berger. Should I buy some Bergers at this early stage or try these freebie Sierras? Border Ballistics are making a separate throating reamer for me so I should be able to extend the throat a little to accept longer cartridges. Ideally I'd like to see the case neck accepting enough of the bullet to make sure the bullet parralllel is fully seated in the case neck.

 

I intend to use N140 but I'm open to suggestions here too. As for primers I was thinking thick cup CCI either BRs or SRMs .

 

Help, thoughts comments etc welcome,

 

Ron

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RS52 powder gives excellent results in my .223 TR (30" 1:8 barrel, Tikka M595 action, CG trigger) with Sierra 80grain SMK's (COL 64.5mm), KVB-223 magnum primers, Privi brass.

 

MV's around 3000fps. Capable of 1 moa off a bipod at 600yds on a flat calm day, and good fun even at 1000yds.

 

RePete

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Ron,you will be familiar with the sorts of issues with the 80g bullets thoroughly discussed back in April 2014 esp by Laurie on here (The Best Long Range 223 bullet).

 

The new 90 Sierra HPBTMK with .563 BC above 2080fps -single load,1in 6.5 twist,might contend-as you say,in a proper rig like yours.

Standard point though on which bullet-individual rifles have their own prefernces for accuracy,so it's try and see-maybe see how your existing 'freebies' shoot,before investing much in alternative?(the canny,but not cannot, approach!!) Good luck with all that :-)

 

gbal

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I'm amongst those that still believe a 90 can't be driven fast enough in a .223 to take advantage of the extra perceived BC points compared to a good 80, especially a VLD such as a JLK or a Berger

 

 

Thanks for the input, what sort of speed is required for the advantage to become apparent?

R

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In your barrel, if you get the chamber / freebore right, the 90s will outperform any 80 currently on the market. 2,900 fps or thereabouts is just possible in an optimal set-up with the 90gn Berger VLD, a bit less with the old (now unobtainable) 90gn Berger BT Long Range. The American FTR shooters aim for ~2,850 fps using the PT&G '223 ISSF' chamber with its 0.169" freebore - which is what I've decided to settle on too these days.

 

The ISSF chamber and its freebore still allows use of the superb 80.5gn Berger BT Fullbore bullet which is more jump tolerant / less finicky than the 90gn VLD. So, I'd strongly recommend that when Geoff 'throats' you barrel, that it accepts this bullet in a round seated to a calibre-depth, ie ~0.23 in the neck. You can push the 80.5 to over 3,000 fps in a 30-inch barrel.

 

I've no experience of the 'new' 90gn Sierra MK which a few US reports suggest is different from the old distinctly mediocre version, and which is much better. As far as I can see though, American FTR shooters who use the cartridge far more than we do, are still very much wedded to the two Bergers. I did fancy a look at the new SMK, but the only supplier I could find was asking more money for them than I was willing to pay.

 

So far as powders go, you'll likely get acceptable results from N140, but still be well down on velocity when you hit pressure issues. I also found N540 to produce sudden pressure spikes. For mildish loads, and which may be a good place to start with in TR, Viht N150 suits the 90s every well indeed. Much higher MVs come with N550, and that is what many Canadian TR shooters use, the 223 very popular there and often with its own class in both TR and FTR. I could never get it to produce small enough groups though for FTR.

 

Alliant Re15 and H. VarGet both work very well and also suit the 80.5. Re15 is temperature sensitive though - even here. I can still remember driving up from Blair Atholl to the House of Bruar 'Harrods of the North' to get an insulated sandwich box back in June 2011 during the SRA Long-Range meeting as a heatwave was seeing me get pressure problems with a hot Re15 load as the days went on and got hotter. Probably 99% of American competitors use VarGet.

 

However, as Re-Pete says, probably the best all-rounder now though is Reload Swiss RS52 which also works very well with the 80.5 Berger. It appears to be less temperature affected than Re15, albeit not as good as VarGet. It will give very high MVs without pressure problems. It is a 'hot' powder - a high-energy type with infused nitroglycerin like Re15, N540 and N550 - so you will wear the barrel out a lot faster than say N150 if you use the performance on offer.

 

Use current Lapua '223 Match' brass. A 'clean'up' neck turn will do a lot of good and no harm. In fact if the chamber neck is a true 0.252", you need it as rounds will be slightly over 0.250" with average Lapua 223 brass and some may approach 0.251". You need at least 0.003" overall clearance, better getting on for 0.004", so brass needs to be neck turned to 0.012" which is what I use with my chambers which are nominally slightly larger at 0.257" neck inside diameter.

 

Do not use any standard Small Rifle primer - far too thin cup / weak for high 223 pressures. The Murom / PMC SR Magnum if you can find any, CCI-450 SRM and CCI-BR4 are the best models for this application.

 

Then .... for long-range everything has to be perfect in your rounds - sizing / shoulder bump; charge weight consistency (0.1gn = 10 fps change); neck tension, bullets batched .... etc, etc. The cartridge is far less forgiving than 308 Win.

 

You will almost certainly run into two other problems. 1) with any bullet weight on shooter-marked targets - the reported 'Miss' as the markers cannot find a bullet hole, especially common on well used target centres with lots of patches; 2) the curse of the 90s - the occasional shot with very poor elevation for no good reason.

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Thanks for the very comprehensive reply Laurie.

 

This latest batch of Lapua match brass measures a very consistent 0.012" thickness. A previous batch (prob from around four years ago was measuring 0.013-0.0135" ) so I might be inclined to work up a load without turning these new cases and see what the results are like. I will order a mandrel and pilot for my K&M trimmer though, I like to have the tools to hand should I need them.

 

This will be my first .223rem build, I'm quite new to this but have chambered a few .308s recently on my new lathe and have been very pleased with the results. I understand it to be a little more finicky though and will proceed with caution. I'll indicate the bore with a Gordy Gritter rod (very time consuming but it seems to be worth it) and use a tight fitting pilot on a Manson floating reamer holder whilst keeping my fingers crossed.

 

I appreciate the comments about powder and seating depths, a single caliber depth is a much better way of saying what I was trying to say when rabbiting on about bullet / case neck parallels!

 

I'll likely start with N150 then, I have plenty of it and use it with my .308 win.

 

I'll post pics when I can and results when they're known.

 

R

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  • 1 month later...

The rifle is basically finished and I'm editing a video I've made of the chambering process. I managed to get a few shots over the chronograph yesterday and 2900 fps seems to be well within reach with N140.

 

Load development will continue but I was getting single figure SDs at 2890 fps with CCI BR4 primer and (quite a lot of) N140. Bullets were moly coated Sierra MK 90grn and 20 thou jump in a .170" freebore chamber with a .252" neck.

 

Interestingly the point of impact for loads trialled with 3 differing weights of N140 were very close together at 100 yards, probably less than 1/2 moa apart.

 

I'll test CCI magnum primers with the same load next and weight sort my cases and report back.

 

Ron

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  • 4 weeks later...

Laurie (and others),

 

What sort of ES could you get with your 90g loads?

 

I can get an ES of 19 across 10 rounds with an average of 2760 fps (SD 8)

 

&

 

An ES of 31 across 10 rounds with an average of 2890 fps (SD 11)

 

Admittedly I haven't been batching bullets yet but powder charges are being weighed accurately. I'm using an Oehler 35p but only a 2" rail. The barrel is still very fresh, around 70 rounds to date.

 

R

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Last time I chronographed my 90gr VLD load with N550 from a 28" Bartlein barrel I was getting 2791fps, ES 9 & SD 4 for 5 shots and was groping about 0.3 of a minute.

I seem to remember that with the new pointed 90gr SMK and RS50 I was getting a slightly larger extreme spread about 12-13 but do not have the exact data recorded, but the velocity was 2797FPS (went up to about 2840 but the groups opened up to about 0.6 MOA)

Both loads were with BR-4s as they are what I have available at the moment but I have found CCI 450s to be a bit more gentle pressure wise with the BR-4s needing a drop in charge of about 0.2gr.

 

All measured with a Magnetospeed V3

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Those are very impressive figures for such a small case. The sample is smaller than mine but all the same, very impressive, can you divulge load details and anything else pertinent? Case prep, batching etc?

 

What distance were you shooting over? I'm not convinced heavy bullets of any calibre run true over the first hundred yards. My .308 win match rifle can demonstrate 1/4 moa groups at 1200 yards but closer to 3/4 mo groups at 100 yards!

 

It's nice to see a one hole group but this rifle will be used between 400-1000 yards.

 

R

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I must say it has taken much attention to get them down (following what Laurie has covered in the past mostly) and I still can not absolutely guarantee every batch will be that low! I pay particular attention to assuring consistent powder charges these days.

I have found consistent neck tension to be critical with my .223. I anneal my cases each firing (maybe excessive - but why not), I also ultrasonic clean each firing and size using an appropriate bushing in a redding type s die and chamfer and de-burr. As of now I do not neck turn but am weighing up if I need to. I do sometimes batch my bullets but sometimes don't, depends if I feel like it - I do suspect that the 90 SMKs would benefit from it though.

As for loads I am currently using 25.1gr N550 with the 90gr VLD at ~2.605" COAL which is 10 thou in (although I measure using CBTO usually). For the 90 SMKs I have been using 25.5gr RS50 at ~2.550" again 10 though in giving (2797fps).

 

I usually shoot this rifle at 300-600y (what we have at Cawdor) but have used it a few times at Atholl and Bisley to 1000y but not enough to make an accurate assessment of performance - I defer to Laurie on this one - but it is certainly fun learning and shows promise .

I have however done a good amount of shooting with both of the 90s out to 600. I have been very impressed with the 90 VLD, it is just as accurate as my 80gr loads but is slightly more tolerant of the wind. When I do my part and in calmer conditions it keeps the majority of shots in the V of the appropriate F-Class Target and rarely lets one out of the bull - assuming you are using a TR target you should have no problems at all in terms of accuracy but with higher ES elevation might be an issue further back than 600.

 

I have not been quite as impressed with the 90gr SMK though, I tried them on the suggestion of Peter Burbridge along with what a few threads on accurate shooter said on the newer pointed ones. Whilst they group reasonably at short range they do not seem to be as accurate at longer distances - they will still hold the F-Class Bull, but often with fewer Vs.

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Thanks again.

 

I'm going to try RS60 tomorrow, seven shot strings at 25, 25.5, 26 & 26.5g. My experience of RS60 is more positive than my experiences with N550, it's seems more tolerant to heat than N550 and performs better the harder it's pushed. I use it for MR purposes and can get SDs of 4-6 across 22 shot strings. I'll be interested to see if it does something similar in this smaller case.

 

All my powder charges have been trickled up using my new Target Master trickler and my analytical scales suggest they're all within 0.04 grains of each other. Cases are batched to within 0.3g and fully prepped. I'm using 0.001" neck tension in my Redding bushing.

 

I'll report findings in due course,

 

R

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Well Sundays shoot went fairly well. Two 2+15 shoots at Blair Adam at 500 yards shooting prone with sling fitted. Harley bench testing (uneven firing points, blustery wind etc etc...)

 

The first shoot was with the slower load (2750fps) of 24.5g of N140 (SD of 9) and it was OK. It was clearly capable of holding the vee but didn't demonstrate any preference for a particular zone, I'd say it was a 3/4 moa group.

 

The second shoot was much better, it was with the faster ammo (2850fps) but with a higher SD of 13 and the it demonstrated a tighter vertical spread which was generally between 1/4 and 1/2 moa.

 

I then trialled some other loads based on RS60. Seven shot strings from 24g right up to 27.5g(!) in half grain increments.

 

Weight - Average Speed - SD

 

24 - 2512 - 21

24.5 - 2566 - 23

25 - 2619 - 31

25.5 - 2668 - 20

26.0 - 2723 - 17

26.5 - 2774 - 15

27.0 - 2830 - 9

27.5 - 2891 - 5 (bingo!)

 

Velocity increase is very linear per half grain increment 54, 53, 49, 55, 51, 56, 60 so I'm happy I'm not doing anything exciting. The weather was quite hot yesterday (for Scotland) and the cases resized easily and primer pockets hadn't expanded (I have made a tool to check this). The decreasing SDs seem to typical of RS60 in the .308 case - the harder it is driven the better it seems to perform. There's room for another grain in the case but I think I'd be quite happy trialling this new load the next time I'm on the range.

 

R

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  • 4 weeks later...

Well I tried a slightly stiffer load and found it worked well at long range. Shooting the rifle as a true target rifle I managed to 98s, one at 900 and one at 1000x. The load is giving 2940 fps with an SD of 8-9 but I'm hoping to see and improvement with sorting bullets and making a truing cut on the case necks. I did notice a handful cases post firing offered marginal friction to a bullet being passed through the case neck so I afford to make a light truing cut.

 

It was the highest score on the day in TR and Club FTR (scoped TR with a rest) classes so I'm not unhappy. Both my first shots were suspect elevation shots and the dropped point at 900x was a declared bad shot. The other escapee at 1000x was a wind change. Obviously the 1000x group is larger than the 900x but I'm pretty happy this is an indication of decent progress and with a few more tweaks it should be a very good target rifle.

 

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