Fast twist/ sabotless

[sw]

I've followed the "new bullet" and higher BC threads with interest as surely have many others. I also realize, many state MLer regulations limit calibers, bullet selection, propellents, etc. I have come to the conclusion that, where possible, shooting sabotless removes the sabot limitations and faster twist reduces stabilization problems. Where legal, a 13 or 16 twist, a 40 cal, sabotless, simplifies accuracy problems; and I would expect a 16 twist 45 cal would be a better choice for either sabotless or saboted 45 cal shooting. Those who live in states that allow down to 40 cal or less, would do well to consider a fast twist 40 cal, IMO.

[edge]

No argument here

I wish I went faster than 14 but can't fault anyone for the slower twists. I would like to play more with a long range ML with a true high BC rifle bullet.
I shoot what others can't at this time but others that have a 14 twist have expressed a problem with there twist rate...at least I have not heard any complaints.

edge.

[Jon]

When I get more reports on the new barrels I will decide who to go with. Since I'm only planning to shoot sabotless from what I'm seeing a 13:1 twist would would be a good starting point and probably a .392/.400 to go full form?

[mountainam]

SW, I was browsing through Mc Gowen's site and they listed Micro-Grooved barrels for .358"cal that have very fast twist like 1/7" IIRC. The thing that confuses me is that they show the same bore and groove diameters that their standard 6 groove rifling has. Am I under a misconception that Micro-Grooving is a shallower cut than Standard? And what are your thoughts on a Micro-groove .358" sabotless ML? We have a .38 cal minimum here in Ohio, but I've never had my caliber checked in the last 35 seasons. I think Hornady's 200gr FTX might fare OK. Just contemplating another project in the off-season.

[spoonover]

Hornady's 200gr FTX, tried them in the 358 Win 14" twist .7" twist wow, must be for a loooong bullet? Harvested two deer and have no complaints, one doe was 100 yards and the other 250. Both did the death run (heart shots) and dropped close to fifty yards from impact. From what I recall there was no difference in wound channels, so here is one recommendation. This is my sight in figures, as can be seen 325 yards is doable!
Input Parameters
.358 Hornady 200gr FTX
BC weight fps zero
0.300 G1 200gr 2700 275

Bullet Trajectory
Range (yards)

Range
(yards) Drop(in) Drop(moa) Wind.(in) Wind.(moa) Time (sec)
25 0.54 2.07 0.07 0.27 0.03
50 2.27 4.33 0.28 0.54 0.06
75 3.66 4.66 0.65 0.83 0.09
100 4.70 4.49 1.17 1.12 0.12
125 5.36 4.09 1.86 1.42 0.15
150 5.62 3.58 2.71 1.73 0.18
175 5.46 2.98 3.75 2.04 0.22
200 4.85 2.31 4.97 2.37 0.25
225 3.75 1.59 6.38 2.71 0.29
250 2.15 0.82 8.00 3.06 0.32
275 -0.00 -0.00 9.84 3.42 0.36
300 -2.73 -0.87 11.90 3.79 0.40
325 -6.09 -1.79 14.19 4.17 0.44
350 -10.11 -2.76 16.72 4.56 0.48
375 -14.84 -3.78 19.52 4.97 0.53
400 -20.33 -4.85 22.57 5.39 0.57
425 -26.63 -5.98 25.91 5.82 0.62
450 -33.81 -7.17 29.53 6.27 0.67
475 -41.92 -8.43 33.45 6.72 0.72
500 -51.04 -9.75 37.67 7.19 0.77

[sw]

Jun 9, 2011 6:37:07 GMT -5 mountainam said:

SW, I was browsing through Mc Gowen's site and they listed Micro-Grooved barrels for .358"cal that have very fast twist like 1/7" IIRC. The thing that confuses me is that they show the same bore and groove diameters that their standard 6 groove rifling has. Am I under a misconception that Micro-Grooving is a shallower cut than Standard? And what are your thoughts on a Micro-groove .358" sabotless ML? We have a .38 cal minimum here in Ohio, but I've never had my caliber checked in the last 35 seasons. I think Hornady's 200gr FTX might fare OK. Just contemplating another project in the off-season.

Some thoughts. I first heard of micro groove rifling in Marlin's 22's in the late 50s or early 60s. In std rifling I think the depths are normally .004", some down to .0035". I think micro-groove rifling would lend itself to smokeless, sabotless muzzleloading. The stated caliber is the bore, not the distance between lands which is important to us muzzleloaders. We want our bullets to fit between the lands and obturate , upon firing, into the groove. In CF, the bullet is groove sized and is jammed thru the lands upon firing which is what causes the extreme, initial pressure rise. Some of us duplex to help duplicate this pressure rise.
RB and I talked about this about 10 years ago when he was so frustrated with his 1st 45 cal PacNor. Somehow the 451 (pistol) PacNor barrel just didn't work well: the 450 bullets just wouldn't go down. We agreed that a 458 Win would work better. I told him that if the 458 worked well, I wanted a 408 Win to see if a 40 would work. My 45 didn't work well but my 40 was wonderful. I got both about the same time. My 45 turned out to be one of the "off-sized 45s with a 0.4535" land to lane difference. I have 2 other properly sized 45s now which work great. With 452 bullets, significant re-sizing must be done to get down to slightly sub-450 so it will go down the barrel. Even the exactly 450 Parkers won't go down well w/o resizing in my 2 normal sized 458s.
My 408 Win barrel is 401 and light knurling is just right.
Now to the 358 microgroove: what is it's land to land difference? 354-355? You'd have to size down to slightly sub-land-to-land, then knurl. Then, the main problem, IMO, how much initial pressure can you get to get enough obturation of this long, tough bullet to be accurate. Might not be that hard, I don't know. Most of our concerns such as this( like sabots stripping in faster twists) have turned out to not be a problem at all.
What is the caliber of a 38 Special? I don't think a 358 barrel will present a problem with the 38 cal rule.
Hope this helps.

[rossman40]

I think the Ohio DNR put the .38 caliber rule for muzzleloaders in to stop guys using .36 cal squirrel rifles on deer.

[spaniel]

Indiana has been relatively progressive on the centerfire front (rifle are allowed that meet requirements to keep their power down but still allow 400-500 yd wildcats) but we're still stuck with the 45cal requirement or I'd already have a .40. In retrospect I do wish I'd gone with the 1:16 instead of 1:22, but I was thinking of all the rotten luck people used to have with the 1:20 smokepoles.

[Jon]

If you built a 40cal. I was thinking about a .392/.400 in a 1:13 twist so I could use a .400 bullet especially with the new .400 that is being worked on now any thought from anyone? This would be full form sabotless.
Jon

[swinglock]

Well, perhaps this is a good time to toot the horn but with some reservations as no one knows it all or has done it all.

This might feel a bit off course but it relates directly.

For about 5 years I have been building and testing rifles made almost exclusively for shooting sabotless bullets and for more than 3 years have been shooting a lot of different varieties of modern jacketed high power rifle bullets some of which have very high ballistic coefficients. Many hundreds of bullets have been shot.

Bullets used have included everything from plain smooth shanked, knurled shank, flat based, boat tailed, varmint, match, hunting, solid copper, solid copper annealed and even some solid brass turned .416 cal. annealed match bullets.

At first, some bullets were resized all the way down from standard groove diameter to a bore diameter fit and other bullets were selected which required no resizing or only slight resizing. Bullets were shot using various types of wads or combinations of wads even including copper gas checks.

All kinds of combinations and methods could be described and discussed but, IMO the most important development contributing to the shooting of sabotless bullets is the adjustable FULL FORM sizing die. I feel that way because it paves the way for a shooter to " easily " use bullets of almost any type including the most modern designs having the highest ballistic coefficients or other desirable attributes.

Full formed bullets can be shot accurately at low or high pressure levels. Because they produce a much better seal than land riding bullets, I have never had the need to use any types of over powder wads or gas checks. They can actually be sized to load more EASILY than land riding bullets without degrading reliability of ignition. Accuracy is as good as has ever been achieved. Full form resizing is no more difficult than smooth sizing. No knurling needed.

At present, load development and testing is being done for a couple of light weight .416 rifles using full formed bullets.
Accuracy and performance is great!!!

In a nut shell, for anyone wanting to build a rifle for shooting high ballistic coefficient modern rifle bullets, my suggestion is to simply select the caliber you want and the correct barrel for the bullets you most want to shoot. Then , send Swing-Lock the barrel drop so they can make you the required full form bullet sizing die. I off course would love to build you a complete rifle. Any caliber can be built.

I'm happy to answer any questions and welcome PM's, e-mail to [e-mail] or call [phone]

Thomas Post
Swing-Lock Custom Muzzleloading, Inc.

[Dave W]

Tom, could a full form die be made for a micro grooved barrel? TIA

[swinglock]

Dave,

Yes. No trouble at all.

[sw]

How about us 40 PacNor, 16 twist, shooters who have had our barrels for awhile?

[500cadillac]

So is a full form die like a Lee push through die except you use a piece of barrel?

[swinglock]

sw,

A full form die can be provided for the 40 PacNor if a barrel drop is provided. That of course depends upon whether or not one wants to live with a shorter barrel. The barrel drop should be of at least 1 In. long.

500,

The full form die is much like a Lee die except that there is a sizing element installed into the die body which is made from a drop piece of rifle barrel.

If you go to the web site " swinglock.net ", a fairly lengthly description of full form dies is shown.

Tom

[Deleted]

Spoonover,
It might be doable but over 14" wind drift at 325yds is more of a challenge for poi than the drop to account for. Thats with a bc of .3?? . The parkers are just made for that longrange stuff and are going to be hard to beat.
Sabotless is not new but there are new techniques emerging in
its following. I hope I can keep up.
Keep it up guys,
Greenhorn

[savagebrother]

this is a .358 shilen ss match barrel it has a .3575 land and is very smooth, it has a .380 falsed muzzle 1/2" long. so far 60 grains of 3031 is shooting well arounf 2700 fps as is the case i think 2800 is very achievable. it shooting right at 1" at 100 yds. i run hornady 200 interlocks thru a 3575 sizer and then one roll on the files and there ready. just getting over back surgery and will be shooting more now.
sb

[deadon]

SB, Glad to hear you are doing better. Looking forward to the pics of your targets.

[deadon]

Tom, I am very tired of fliers shooting with a sabot. I have a 26 inch Dave D 1 in 22 twist 45 cal pacnor. If I send you my Rifle what would you charge me and how long will it take to cut an inch off the barrel ,re crown, re install, set proper head space and make me a full form die? If I forgot anything Please explain and add the cost. also I would like you to shoot it and send me the targets.Thank you Sir, Rusty -------PS, is a 1 in 22 twist fast enough to expect MOA accuracy and consistency out to 300 yrds or am I urinating in the breeze?

[Billy]

Thanks for asking that question, Deadon. I'm interested as well.

[sw]

Jun 13, 2011 18:40:56 GMT -5 swinglock said:

sw,

A full form die can be provided for the 40 PacNor if a barrel drop is provided. That of course depends upon whether or not one wants to live with a shorter barrel. The barrel drop should be of at least 1 ".



Tom

Tom,
I am so pleased with my 40 cal thar I don't want to "rock the boat" so I will leave it as is; however, I like the 40 so much, I will likely get another and try to sell one of my 45 cal barrels. Now, for me and any other potential 40 cal purchasers , I currently have a 16 twist, 6-land PacNor barrel. I'd like to get a 13 twist 40 cal barrel next. The 13 barrel only comes in 8 lands: and problem with your making a die for it?
Thanks,
Steve

[sw]

Jun 9, 2011 6:37:07 GMT -5 mountainam said:

SW, I was browsing through Mc Gowen's site and they listed Micro-Grooved barrels for .358"cal that have very fast twist like 1/7" IIRC. The thing that confuses me is that they show the same bore and groove diameters that their standard 6 groove rifling has. Am I under a misconception that Micro-Grooving is a shallower cut than Standard? And what are your thoughts on a Micro-groove .358" sabotless ML? We have a .38 cal minimum here in Ohio, but I've never had my caliber checked in the last 35 seasons. I think Hornady's 200gr FTX might fare OK. Just contemplating another project in the off-season.

A better answer for you now: call Dan at McGowen and ask. I've talked to him recently and benefited from the conversation. Before I order another 40 cal barrel I will consider McGowen, depending on what they make and Tom's advice on a custom die for bullet sizing.

[swinglock]

Deadon,

You would need to do your own load development and testing as I only develop and test for Swing-Lock rifles. But, I have no problem with cutting and recrowning your barrel and making the full form bullet sizing die for you.

Your twist rate of 1:22 is fine.

To get the work done, send ONLY the barrel and receiver assembly. There is no need to remove the barrel from the receiver to do the work so no head spacing is required.

Cost for cut and recrown including shipping would be $75.00 assuming original packaging can be reused.

Cost for the bullet sizing die including punch, written instructions and shipping is $183.00.


Steve,

I will be happy to make you the bullet sizing die for any barrel you choose. Caliber or twist makes no difference.

Thanks,

Tom