Author Topic: .25 cal 51 gr. NOE Bob's Boattails (Read 43054 times))

K.O. · « **Reply #80 on:** July 31, 2016, 06:50:58 PM »

the reason I keep talking about lightening the rounds is because for the most part no matter the weight/lenth of the round I want my velocity to be in the 800-950 fps range... and a longer light round is one of the things I want to explore

along with weight forward hollow base and how they react to being under/over-spun in terms of accuracy at different ranges.. such so forth and on...

aceflier · « **Reply #81 on:** July 31, 2016, 08:30:17 PM »

If anyone gets these sized right for the GM Mrod barrel I would REALY like to try them out. I'll pay for em just let me know. Thanks!

K.O. · « **Reply #82 on:** July 31, 2016, 08:39:17 PM »

Quote from: aceflier on July 31, 2016, 08:30:17 PM

If anyone gets these sized right for the GM Mrod barrel I would REALY like to try them out. I'll pay for em just let me know. Thanks!

Have you tuned your Mrod up in fpe any... Mine is at 50 fpe stock, 1% es for 9 shots... point is with a 50g projectile in the short 19" barrel, velocity will likely be down in the low 600s or so...

aceflier · « **Reply #83 on:** July 31, 2016, 11:20:44 PM »

It's getting up to 820fps with 43.2 EJ's. Flush hammer striker, Hogged valve light poppit spring and .187 ports. Hopefully more with the bolt mod on its way. I'm thinking about some rat snipers to test also.

K.O. · « **Reply #84 on:** August 01, 2016, 10:33:27 PM »

well that is about 65 fpe and about the bare min needed...it would not show of the best side of the round but could work... about 750 fps or so...

just the barrel being .5" could cause harmonic probs with no further velocity to try and catch a sweet spot with..?

rsterne · « **Reply #85 on:** August 01, 2016, 10:35:48 PM »

That's what barrel tuners are for.... tuning the barrel for your velocity instead of vice-versa....

Bob

K.O. · « **Reply #86 on:** August 01, 2016, 11:37:54 PM »

Quote from: rsterne on August 01, 2016, 10:35:48 PM

That's what barrel tuners are for.... tuning the barrel for your velocity instead of vice-versa....

Bob

Well Sensei yes and no... imo... with the thinner barrels it just sometimes does not work... me I honestly feel they are better at fine tuning the sweet spot than gross corrections of not being close to one...

owen · « **Reply #87 on:** August 02, 2016, 01:01:22 AM »

I received my FN mould today. I only cast 8 bullets, was trying to hurry so I could chronograph them in the failing light. Only 4 filled perfectly. I shot 3 over chronograph, but the valve stem broke on the first shot. I shot this gun every evening for the last week or so. I even killed a 15 lb. woodchuck last evening with it, but when I put one of Rsterne's creations in my gun it broke it. What kind of omen is that?... LOL. Anyway, the driving band measures .2571", so I'm going to have to buy the universal die and sizing stuff, from NOE. The one bullet that I weighed is 51.52 grains. I'm going to modify the mould to have two HP pins. I wanted full control of pin diameter and shape, that's why I went with the FN. I'll update as I proceed.

K.O. · « **Reply #88 on:** August 02, 2016, 01:23:29 AM »

Thanks for the update.

sorry about the stem..

rsterne · « **Reply #89 on:** August 02, 2016, 02:17:03 AM »

OWEN?.... OMEN?.... am I the only one who noticed that all you need to do is flip the W over to get an M ?

Sorry, I couldn't resist.... *grin*....

Bob

nielsenammo · « **Reply #90 on:** August 02, 2016, 01:29:45 PM »

Quote from: rsterne on July 30, 2016, 04:46:08 PM

The TJ's .25 ACP liner is 14" twist.... Both the NOE and LBT 51 gr. BBTs are stable in it.... What I would really like to know is how they work in a GM barrel in an MRod, they are 15.5" twist....

Bob

Dairyboy who has a .25 WAR emailed Jim about the barrel. It is a TJ liner with 1:22, .250/.243. I believe that was Mike's barrel he had them make.

rsterne · « **Reply #91 on:** August 02, 2016, 03:12:25 PM »

You are correct, Mike (CarsonRatSniper) had TJ's make a 22" twist barrel, primarily for pellets.... Until that was made, the only .250 cal barrel available from TJ's was the .25 ACP barrel, which is 0.250/0.243 with a 14" twist.... Those are the only ones I have used.... I don't know what W.A.R. uses for their .25 cal barrel....

Bob

nielsenammo · « **Reply #92 on:** August 02, 2016, 03:34:10 PM »

According to WAR (from Dairyboy), Jim Gaska emailed him that the barrel they are using a 1:22 twist rate from TJ .250/.243.

Based on what I read this bullet will not work in this barrel.

rsterne · « **Reply #93 on:** August 02, 2016, 04:44:01 PM »

That is likely correct.... The 41 gr. should be fine, although it is designed for a 20" twist.... It is at Last Call at the present time, and is available in either 0.250/0.252" or 0.253/0.255"....

http://noebulletmolds.com/smf/index.php/topic,1319.0.html

Bob

aceflier · « **Reply #94 on:** August 02, 2016, 08:57:41 PM »

Quote from: K.O. on August 01, 2016, 10:33:27 PM

well that is about 65 fpe and about the bare min needed...it would not show of the best side of the round but could work... about 750 fps or so...

just the barrel being .5" could cause harmonic probs with no further velocity to try and catch a sweet spot with..?

With the modified bolt it is now getting 885fps avg up to 75ft lbs is that better?

K.O. · « **Reply #95 on:** August 02, 2016, 11:07:59 PM »

Quote from: aceflier on August 02, 2016, 08:57:41 PM

Quote from: K.O. on August 01, 2016, 10:33:27 PM
well that is about 65 fpe and about the bare min needed...it would not show of the best side of the round but could work... about 750 fps or so...

just the barrel being .5" could cause harmonic probs with no further velocity to try and catch a sweet spot with..?

With the modified bolt it is now getting 885fps avg up to 75ft lbs is that better?

It certainly buys you a little bit of flexibility fps wise... For me reaching about 800-850 fps with this round would get me to buy the mold... and will probably happen in a while... You need to slug your barrel to find out what you have for bore and groove...

But you are still probably best served by the 40g .25 BBT ...

the 40g .25 BBT well fpe wise in my mind will allow turning up and down to see about finding a sweet spot... hopefully would work great from 800 fps on up to 950 or so... then you could turn down fpe for jus' plinkin'...

owen · « **Reply #96 on:** August 04, 2016, 12:33:25 AM »

I cast 528 of the 51 FNs. I don't have the resizing stuff yet, but now I'm ready for when it arrives. I modified a stock valve stem and could only get it to shoot 31.02 gr H&N Grizzly pellets to 1089 fps. The homemade valve stem, which broke, was propelling these 31.02 gr pellets to 1123 fps, and it wasn't nearly turned up all the way. The gun is now turned up all the way and is only getting 1089 fps. So I'll have to make another like the one that broke, but not drilled as deeply, etc. So anyway, I put one of these 51 gr FNs (51.52 gr) over the chronograph and got 965.6 fps for 106.69 fpe. If I get the same improvement as Bob did, from resizing, then that could add 20 fps. And an improved valve stem might add another 20 fps, so it's possible that I'll get these to shoot around 1000 fps or so before I'm through. By the way, my barrel length is presently 16.25", 18" Airforce barrel with 1.75" removed (chokeless, now.) So far I haven't shot these at a target. I don't really see the point until they're sized, but I may try it anyway, just to see what happens.

owen · « **Reply #97 on:** August 04, 2016, 11:01:03 PM »

Before shooting at the 50 yard target, I took an empty screw on top pellet tin, wiped it out, added 2-drops of Motorcraft 5W-20 synthetic motor oil, then added approx. 50 of the 51 FNs, closed the lid and spent 3-4 minutes swirling this around until a very thin even coating was achieved. The first 3-shot group was a perfect triangle with 3/4" between each hole. That group shot 2.5" low, 1.25" left of where the gun was sighted in for H&N Grizzlies at 1100 fps avg. I made the turret corrections and shot another 3/4" group that covered the center dot of the target, but was .25" too far right. Amazing! I didn't even want to shoot these unsized as Bob had stated earlier in this thread that his resized bullet groups were "about 1"." He was probably shooting 5-shot groups though. I shoot 3-shot groups because yesterday I chronographed 3 Grizzly pellets in a row which gave 1085, 1089, 1085 fps. I've not changed any power setting since then. I haven't chronographed 3 of the 51 FNs in a row, yet, but I believe that they're very close also, based on the group size. For now, I can continue my war with the woodchucks just fine with this kind of accuracy, 1.363 moa. I'm really hoping that resizing will get me into sub moa territory though.

rsterne · « **Reply #98 on:** August 04, 2016, 11:50:45 PM »

Sounds like you've already got a great combination....

Bob

K.O. · « **Reply #99 on:** August 05, 2016, 12:10:59 AM »

Well it seems Owens Omen turned out to be that your rifle was "Owen" you some good groups in return for you attentions..

sorry could not resist..

1.3 moa first groups at 50 yards... That is very encouraging...sub moa at 50 seems very possible and it seems 1:16 is enough twist with a L.W. barrel...

Hey did you chuck the cut off part of the Barrel... I could send a few bucks to mail it...want to take some pics to compare to the MRod and Trail XL rifling (and any other I can get hold of also)... according to specs it is way taller... also I want to measure/aproximate land width I have .22 and .177 L.W. ...

Like I was talking about early in the thread it just may work to semi/bore ride the nose if there is enough land width to let it ride the "rails"... just might be worth trying imo...

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.25 cal 51 gr. NOE Bob's Boattails

Author Topic: .25 cal 51 gr. NOE Bob's Boattails (Read 43054 times))