16 twist 45 caliber remigton 700

[Ga.Smokey]

Well the last couple days has seen some mixed results.
I was so excited about tge 16 twist and I still am.
Had a few setbacks that I'm addressing.
First setbacks was a huge change in environmental conditions.
Showed that my barrel preasure point wasn't working out. As the barrel heats up it was pulling the action around distorting my groups opening them up considerably.
Showing up in longer range seasons
This became much more apparent after sealing up the load.
In essence creating a new preasure curve.
My thought that fixing the crown created a much tighter seal on the sabot making the burn much more effiecient.
After free floating the barrel it was much more consistent.
In that I'd make changes and the gun reacted predictably. Change back it went back to where it was before.
So basically I'm at square one and will fall back on powder charge and rework back up to find a node the current setup likes.
I also made another change but I'm not ready to share yet as I'm not sure it will work the way I intend.
More ti come tomorrow.
John

 

[Ga.Smokey]

Ok today was a slow shooting day but an important one.
I pulled out the chrono and ran a velocity test starting at 53 grains of powder to 57 where I had been shooting.
The 53 grain load I fat fingured the chrono reset and missed the number but I believe it was just below 2400 in the sweet spot.
The 54 grain was at 2419
55 at 2491
56 at 2535
57 at 2546
I was surprised at how fast they were shooting
I exsoected higher numbers but not 200 ft/sec higher.
So I believe the crown work has greatly improved the seal I'm getting on the sabot.
But at these velocities it's a bit much for thr sabot to handle which explains the accuracy loss.
I've also added a muzzle brake for the sabot loads and made a higb precision funnel to aid in alignment of the bullet/sabot.
Attached are the pics fir today of thr progress.
I am hopeful it all comes together tomorrow.







The muzzle brake is a directional cross hybrid radial brake.
Seems to be very effective so far.
Tomorrow should show the tale of the tape.

 

[Ga.Smokey]

Well things are looking bright fir tge 16 twist went out this morning with 53 grains of IMR 4198 A 225 furry 402 and tge light blue 215m primmer.
Used the new funnel and shot thru the muzzle brake.
Shot 3/4 center to center 100 yards I'm getting happier about this twist and everything I've learned.
Special thanks to Mt monkey and nine ring for there help and pushing me to move forward.
Getting close to completion on the sabot portion of this project I'd like to try 52.5 with a cci 200 next.
Be intersting to see how the bore riders perform. Especially the heavies.
John

 

[Ga.Smokey]

The 3 shots are cold bore and 2 follow ups a minute apart.
I could certainly hunt with that performance but I'm looking for a little bit more.
I estimate based on previous chrono work 2375.velocity.

 

[Ga.Smokey]

As you guys might guess this is an experiment in a new territory for me and slot of others.
Me being fairly new to smokeless I've gone in directions of known performing bullets
Like the furry that have been known to shoot in other twists. Before I move on to other bullets and configurations. As kinda of a base line to try and replicate performance of other twist rates in a similar situation.
I've learned so much in this process its very humbling even with many years of shooting I'm still interested in new to me things and how to possibly contribute to the advancement of what we're doing.
I hope this process of research has been informative and interesting to follow along.
I'm looking for feedback from the group.
I have a couple more tests to do on the sabot loads 52.5 and 52 grains and then what?
I'm limited in my sabot bullet selection so that's a factor also.
I would like to try a light pistol bullet 180 gn with a light charge in the 2000 ft sec range.
but beyond that i dont have anything else to try.
Should I try more sabot loadings or move on to bullet to bore work. I have 50 sabots left fir now.
I have probably 6 or 7 bullets that would keep me busy with bullet to bore.
Your thoughts and suggestions

 

[Ga.Smokey]

Ok so I've ordered some 240 ots 250 star tips and 275 startups to continue the sabot quest.
Also some 180 grn 40 cal pistol bullets to try
More to come

 

[Ga.Smokey]

Tgr last few days have been rainy here so I took the opportunity to right a couple things on the 16 twist.
My last time out started beautifully with a cold bore shot and the next 1/4 to 3/8 apart.
The next shot was well way off the mark.
It wasn't me I called a good shot at the break.
I've shot enough ti know when a shot is good. Or I've spanked one.
We're talking 8 inches right and 3 inches high.
My first thought was I'd blown the scope up so I shot a few more.
My POI had changed drastically further making me think I'd wrecked the glass.
So I brought the gun up to the shop and set it aside and contemplated where I was at with this gun and what I had and hadn't done in the haste to get to shooting.
I'm still learning the ins and outs of building these guns and have a ways to go.
I really thought scope or load was to hot or something was wrong with the gun.
My first reaction was to lessen the load to 50 grains after seeing tge chrino the other day.
I even dropped 6 charges and loaded modules prepped bullets etc.
Well it rained and after going over the check list I realized I'd broken my own protocol fir accuracy .
I had tried a preasure point and now a free floated barrel but never got around to pillar blocking or bedding the action.
So I pulled the glass and flipped over the rifle to separate the barreled action from the stock.
To my dismay the front action screw was barely hand tight.
You can imagine that sinking feeling coming over me as I realized that tge last few days of frustration was thr action slopping around in the stock.
So the last few days I made pillars on the clausing and set it up to do a bedding job.
I'm a Machinist by trade so the machine work is really good.
The wood work on the other hand shows a carpenter I am not.
The bedding came out ok fir this project but I'd want it a little cleaner looking if it were for someone else.
My very first set of pillars I've made.
Not my last.
I'll use 303 stainless instead of aluminum next time fir a smokeless muzzle loader.
Savage needs some love next.
Added some pics of what i did and how it came out.
if there is interest I can start a new thread detailing how I did the process.

 

[ElDiablo]

Curious, what did you have those action screws torqued to, @Ga.Smokey?

 

[Ga.Smokey]

Curious, what did you have those action screws torqued to, @Ga.Smokey?

35 inch pounds
I shot today at 50 inch pounds and took the torque wrench and checked everything between shots
Ran the air cooler between shots..
And the gun was more consistent but not where I want it.
It showed glimmers of hope but the groups were terrible. 4 inches
The Garmin worked very good. And the shot disbursement showed up in the chrono.
50.2 grains averaged 2318 but the SD was 39 ft/sec.
Not going to get it.
Maybe over tge weekend I can go back up in charge and find something to bring it all together. Get that average up a bit.

 

[Ga.Smokey]

Well I'm getting closer to my goals
I learned something today that really makes alot of sense to what I've been seeing.
As you guys might remember my first experiences with smokeless cam by way of variflame ignition which are known to be a bit leaky....
This build is with a different plug with brass modules.
The variflame headspaces on the bottom of the adapter.
So I headspaced the modules the same way.
Well that appears to be a flaw in my thinking.
Mt monkey sent me some modules to try that had been shot and they were clean as new borns bottom.
So I started wondering why mine weren't.
After looking at the plug I realized maybe I had a miss match of plug and modules.
So how to correct.
I made a spacer sleeve that fit into the plug to take up the missmatching of dimensions.
That seemed to work out pretty good and even though I shanked my third shot today in a hurry to get the shot off before dark
My velocities are stabilizing and are much more consistent.
Getting closer need more range work at 100 before stretching it out to 500 or so.
By the way the garmin is life changing.....
The 3 shots are in the teens on SD and spreed although high at 37 is much better.
Better than half of what I saw earlier this week this is a small sample in changed conditions so more testing is in order to see if the trend continues.


The single was shot first the next two an hour latter as the rain caught me And had to wait it out.
It's very intersting to see how much better a good seal can help a rifle out.

The top two are cold bore an hour apart the lower I shanked low.
I saw it as the shot broke dipping.
The gun is front heavy and if im not up on the stock it can do that on me...

I'm still learning about building and that's part of the fun for me the quest for knowledge.
I did try some wads
Intersting thing I found was a velocity drop but a more consistent across the board number
I theorize that the wad helps seal but also decompressed the load accounting for the drop in velocity.
More testing to know for sure
Tomorrow's testing will shoot groups with and without wads
Current load is 53.1 grains of I4198 225 furry 402 with a HLB
I'm also curious as to the obvious higher velocity with this barrel and twist rate.
I have another barrel waiting in the wings in 16 twist once I get the build process sorted out.
This project has been intriguing to say tge least very educational fir sure.
Thanks to Mt monkey knowledge and advise the build is progressing very fast
I'm set up to make some changes next week to sure up the platform but I'm not ready to disclose those until I see if it works.
The mad scientist work continues.
The positive for me is the numbers are more consistent and now the changes are making predictable outcomes.
Sometimes you don't know what you don't know till you know....
John

 

[ElDiablo]

I theorize that the wad helps seal but also decompressed the load accounting for the drop in velocity.
More testing to know for sure
Tomorrow's testing will shoot groups with and without wads

My thinking as well. I’d like to see data on 5-10 rounds with and 5-10 without a wool wad. How much difference does that little bit of space/compression change velocity (pressure)?

 

[Ga.Smokey]

Well I'm back in from this mornings shooting. It was a brisk morning 40 degrees Farinheight sunny and started out calm
By tge end it was blowing with a half value left wind at 45 degrees across the range out of the nortwest. Over my right shoulder static at 8mph gusting to 18 mph
At 100 yards the wind wasnt much of a factor.
My test today was with out brake with thread protector. I want to verify a baseline. Later adding tge break ti see if it hurts accuracy.
More in that later on.
I've made so many changes really had to get back to basics.
So my protocol is 3 rounds of standard out of the pack furry bullets.225 HLB 215m
primmer. Out of tge pack the fury measured .4015 at tge olive tangent junction of the shank. .402 in the middle and .4022 to .4027 at tge heal some with. 0004 egg at 90 degree
Same load with a wad.
Tge intersting thing that I noted yesterday was indeed there was a 30 ft/sec velocity loss and 12 feet decress in SD the group was better.
So that sent me down the wad road so I fired 3 sized bullets at .402 more round and straighter from the midline of the shank
Best group of the day
Velocity still lower yet but again better SD numbers.
So I had 3 more shots so I wanted to now see if without the wad and with a smaller bullet tge velocity would do.
I had .4015 bullets that ran without a wad
The velocity increased to similar numbers as the first pass of thr day.
Best SD and ES of the day. Worst group as I pulled the 3d shot low. Beginning to be a thing with that stock and full bull barrel.
If I don't get it just right on the front rest it Teter toters and tge shots fade low.
I believe that shot hit where it broke I saw it dip at the Crack of the shot.
Anyway it's intersting for sure
My protocol was a 5 minute break and run my air cooler in the barrel while I looked for sabots I found a few and to my surprise they look very good
Pics of the day

 

[Ga.Smokey]

Taget pics the black paster is .875 across the diagonal

.4025 no wad

.4025 with wad

.402 with wad

.4015 no wad

 

[Ga.Smokey]

Chrono data

 

[Ga.Smokey]

I think I need to flush out the size this set up wants going to try .401 /.4005 / .400
Without wad if I find something I like what I see I'll try wads to.

 

[Ga.Smokey]

Back out at the 100 yard line today with thr 16 twist.
Made some wholesale changes to the gun to make it more in line with other Platforms I'm used to.
The big change was to drop the action into a aluminum chassis. Like my 6.5 precision rifle.
So all my shooting is consistent across the board.

I'm also going with a bipod going forward the front rest just isn't comfortable for me.
I need to set up a rear been bag as the rest bag shown is ok at best for this set up.

So off to the shooting
With the changes made I thought some getting used to the new set up was in order.
I thought how canbi get some trigger time without breaking out thr good stuff.
I had some 180 grain jhp
zero bullets from my uspsa days sitting here.
They are .400 over the mics give or take a few tenths stuffed in a HLB they gave a loading force of about 15 pnds and a seating force of 30pnds. In a clean barrel.

On the range I had 6 rounds with 45 grains of 4198 and federal 215 primmers
Loading using the spin jag and tgr ramrod seating stop.




Thr shooting was 6 rounds over 10 minutes.
I didn't have a great amount of time.
The velocity numbers kinda show the story that the bullets probably need a little help .400 is a little lesser than is needed for top accuracy. Probably need to up the load force. 20 lbs as worked the best so far for me.
Cooling the barrel probably wouldn't hurt either.

The group ended up being a shade over 2 inches.
Not great but it really shows promise as a light plinking load that costs a fraction of what others cost.
500 cost me 70 dollars so I am interested in experimenting a little more.
I started with a squeaky clean barrel will be intersting to see how a fouled barrel reacts.
I have 6 rounds on this clean.
It's surely pie plate worthy
Is it what I'm looking for not really
The intersting thing is the vertical stringing directly correlated to tgr velocity. So to me sealing up the sabot a bit better or changing to a standard rifle primmer could even things out.
Enjoy

 

[Ga.Smokey]

Any thoughts from the experts as to how to better seal up the bullets/sabots
Knurl up / paper patch and resize??
Suggestions appreciated.
Need to get up to .4015

 

[LBAhunter]

Any thoughts from the experts as to how to better seal up the bullets/sabots
Knurl up / paper patch and resize??
Suggestions appreciated.
Need to get up to .4015

Change powder besides 4198. 180 gr and 4198 is probably pressure starved. I don't think wads, paper, or etc will help.

 

[Ga.Smokey]

Change powder besides 4198. 180 gr and 4198 is probably pressure starved. I don't think wads, paper, or etc will help.

I have 4198 322 n120 rl7 availible .
I'm running 45 grains of 4198 for 2100 to 2200 vel
My thoughts was a tighter seal on the sabot/barrel bullet for more resistance for better initial start preasure.
I think that would even out tgr velocity.
As is it's really soft and pleasant to shoot.
Thanks for the reply.
John

 

[Ga.Smokey]

Got out today to investigate the light bullet again.
The test was 3 rounds with bullets knurled up to .403 and sized down to .402 in thr harvester LB with a further reduction in charge weight to 40 grains ignition by a cci200 .
It's a small sample but shows promise with a fast twist and light bullet at very modest velocity and almost no recoil.
I wasn't shooting all that well today so I stopped shooting till this afternoon.
It's intersting to see the coralition of bullet size loading preasure and the SD and group size.
Load force was 20pnds
Set at 30 pnds.
The first two shots were tight openning the group on 3d shot
An analysis of cost shows thst load under 1.50 per shot.
not a terrible little plinking or intro to smokeless load for the grandkids
About like a 243 in felt recoil...
Enjoy.