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Hello from Scotland~

I wonder if you gents could help me with my current handloading project ?

Im going to load Hornady 170 gn Flat nosed bullet in my .308 Miroku M-bolt.

I make the Hornady bullet 0.990" long, i loaded one into a neck sized unprimed case out to 2.92" and slowly closed the bolt.........i did this several times each time getting a O.A.L of 2.792" Reckon Miroku's must have long throats !

From this im thinking of seating to O.A.L of either 2.790" or 2.788" ???

But thats a long way out and im worried how stable the bullet will be in the neck of my collect neck sized cases ? The bullet is well up the neck !

This being a "short" bullet in a long throat how much of the bullet should i keep within the neck ? Is it ok to have it so far out ??

Im wondering if i should get a lee factory crimp die to hold fast the bulet in the neck .....or seat it a little deeper ??

Im looking to load around 41 gn of N140 behind this bullet im lookintg for approx 2400 f.p.s

Englander
 

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Englander
From your description it is not known how tight your brass is grippin' the bullet, and your measurement may be at a point of firm or better contact with the rifling. Try seatin' a bullet to below the neck a bit to stretch the neck a little and then pull it and use that case to check your seatin' depth agian, it will probably be somewhat shorter. Generally I use a seatin' force for breach seated bullets of only 2-4 lbs. The method you are using if the brass is a hard grip on the bullet can take much more.
If they feed and extract O.K. with out distorting the concentricity or pulling the bullet to make your o.a.l. greater at whatever you decide on for an o.a.l. they will be O. K. to handle, PRESSURE however is a different ball game.
Start low and work up is always a real good idea, but extra care is needed when a condition with no freebore is present.
;)
 

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Englander: The rule of thumb is to have a bullet seating depth in the case equivalent to one bullet diameter for best chances of getting and maintaining (through handling) good case/bullet alignment. Deeper won't hurt with jacketed bullets if necessary but you are infringing on case capacity if that is needed so loads should be developed with that in mind.
best
 

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Englander,
If you've any cases to spare, I would set one up to take this measurement for this bullet and any others you may wish to use. I simply take a case that is fired in my chamber and neck size it and cut a slot in the neck/shoulder with a abrasive cutting wheel in a Dremel tool. You can partially seat a bullet, a bit longer than you anticipate the OAL to be, and chamber it to determine where it contacts the rifling. I typically do this 5 times and take the average although it seldom varies more than a thousandth or two. This method is very accurate. I would seat the bullet .020-.025 back from the measurements you take here unless using a Barnes X-Bullet, in which case you should follow the reccomendations of Barnes. This technique will eliminate several unknown factors in order for you to come up with the measurement that you are looking for.

I'm assuming, always dangerous, that the flat point has a nose taper that is not THAT much less than a spitzer type bullet. The shorter overall length, compared to a pointed bulllet of the same weight, likely acounts for the fact that you can seat it out further. The good rule of thumb, as stated by BCStocker, would be to use a caliber length in the neck and to let that determine your OAL. If magazine length prohibits this, load it out to the max length that will reliably function through your magazine. If the cartridge seems long but functions perfectly there is no big deal, just some increased powder capacity. You can easily deal with this by comparing your velocity to loading manuals to be on the safe side. You could also do as I would and just load up until pressure signs are apparent and back off a grain. Unless anticipating shots at long range, which I doubt since you're using a FN, I would load to safe pressures and optimum accuracy.
 

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The Hog Whisperer (Administrator)
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I have some rounds loaded for my 6.5x55 Swede which are just barely seated in the case mouths. Sort of an experiment, trying to load as close to the rifling as possible. A 120gr. Ballistic Tip for those who are curious. This gun has a very long throat.

I doubt that they are even 0.100" into the case (not counting the boattail). And not crimped, either.

But they work - even though the rule of thumb is to load to a depth equal to the bullet diameter. Guess some people's thumbs are shorter than others?

Anyway..... with these rounds, in this gun, for what I use it for, it is enough neck tension. Sounds like you would have even more of the bullet base in the case neck than that, so it could work for you.

Personally I don't load any closer to the rifling than 0.020", although the benchrest competitors sometimes do. My process is to load to 0.020" (or as close as I can get within reason), and if necessary, seat 0.005" deeper into the case in each batch until satisfactory accuracy is achieved.

The only exception to this is the solid-copper Barnes "X" bullet which Barnes recommends starting no closer than 0.050", so that's what I do when loading those bullets.

As far as reducing the bullet jump to the rifling, yes it often helps accuracy, although I have several guns that shoot just fine with a longer bullet jump, so you never know till you try.

Anyway.... try it and see.... that's what handloading is all about. Sounds like you have a good understanding of the process and are ready to learn a few things.

Let us know. Best of luck.
 

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MikeG,
it's not the width of the thumb, it's the diameter that the "rule of thumb" is based on. That said, I'll advocate your notion of experimenting with what works. I have also had experience in single shot pistols in which I had to seat the bullet far less than a caliber and not even come close to the rifling. I simply used the additional cartridge capacity to increase velocity as I was using the rounds for hunting. One thing to be careful of using this technique is to load several rounds, handle them semi-roughly as might be expected in a reasonable hunting situation, and compare the bullet runout as compared to the runout when the rounds where reloaded. This will also give you a, field based, idea of what will be acceptable for your weapon/cartridge combination.

Englander,
your idea of the Lee crimp die may be a good one, but I'd base my results on the resulting bullet runout and actual accuracy of the weapon. I guess it all depends on how much you WANT that bullet to work. If you don't already have a RCBS Case-Master, or similar tool, I recommend it in order to measure bullet runout in a effective and inexpensive way. Excessive bullet runout is a sure fire way to make a very accurate rifle look mediocre.

Good luck with your project.
 

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Hi, Englander:
Seating close to the lands often, but not always, works. Rick Jamison, who shoots before he writes IMO, had an interesting article in the May 1995 Shooting Times. He was visting the in-laws in Germany and didn't have his usual supply of goodies when he worked up loads for a couple of .308s for his father-in-law. He had one powder , Rottweil R-902, and 3 bullets, the 125 gr Sierra SP, Sierra 150 gr BTSP and 180 gr Partition. All bullets were tried in both rifles at seating depths that gave .012", .051" and .129" off the lands.

Results, .012" gave 3 best groups, .051" gave 1 best group and .129" gave 2 best groups. In two cases the best group was less than half the worst and in one almost 4X better. Interestingly, that was the case where the .051 group was best, at .9" @ 100M, while the others were 3.3" seated out and 2.8" seated in.

Bye
Jack
 

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Discussion Starter #8
Range up date

Hello from Scotland~

Thank you gentleman for your input. I loaded up two different lots 2.790" and 2.789" the both work though the box magazine of the Miroku ! which is nice.

I settled on 42 gn of N140 powder behind this bullet. As i was aiming for 2400-2500 f.p.s.................

Today I tried both loads from our 200 yard firing point, im happy to report the 2.790" was giving 3 -shot groups of 2.25" at 200 yards which im very happy with, neck tension seems more than adequate to firmly hold the bullet although i still think a crimp die would be a good idea.

Even better i managed to blag a go of a friends chrono and im delighted with the results.......Average 2461 f.p.s deviation 9.6 spread 19.7 so all in all im pretty happy. And will probably not interfere with it much more.

Englander
 

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The Hog Whisperer (Administrator)
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Well done... sounds like a good load!

Keep in mind that sometimes individual bullets can vary a bit, even from the same box.

If I read your note correctly, it sounds like the bullet is only 0.002" - 0.003" from the rifling? You might consider putting these a bit deeper into the case, at least 0.010" more, just because if you got one that was a bit out of spec, you could stick a round in the chamber in the field.

Another 0.010" shouldn't make any meaningful difference in velocity, and I would expect no change in accuracy, or very little.

Just a thought..... I've had a bullet come of of a case once, while at the range, and it was not fun to get all the powder cleaned out of the action.
 

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always rely on your rifle chambering as a guide rather than strickly sticking to what you see in manuals.
I always make a dummy round and find the maximum col that will chamber in your rifle and compare this to your manual to see what tolerance you have.
then do some testing.
when I first started handloading for rifles,some bullets would not properly crimp in the right place on the bullet if I used the reccommended col.
an instructor taught me how to find the correct col for my rifle.
 

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The effect of seating to the lands is fairly complicated, and sometimes the effect on accuracy is overrated. The support given to the shank of the bullet by the case mouth AS IT ENGAGES THE LANDS is critical. If you are only 1/8th inch into the lands and the base of the bullet is released by the neck, the bullet will yaw in the throat anyway. Shallow seating can also cause large variations in starting pressure. You may be better off seating to the base of the neck and making sure you have full uniform neck grip and/or crimp while using cases fireformed to your chamber. This, combined with a mandrel type neck sizer may give you better groups than seating way out to touch the lands.
 

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Gollllliesssss--------

The further this goes, the more it makes me wonder about the 75-gr V-Max load I've been running through my .25-06. To use such a (relatively) short bullet exclusively a shorter throat could be used, with a deeper seating depth, is that right? Realizing that if one were to load a 117 or 120 in such a chamber the bullet might be infringing on powder space......... It's satisfactory for accuracy, but I'm getting very minimum seating depth. I'm not going to do it, but just wondering ....

in Big Sky Country,

denurban
 

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DIES-

E- Well you learn every day. I was not aware you could reload 'overthere' :) This is just a thought, but you may wish to look at Reddings line when thinking about that die. They are on line, and if there is any further help needed there, just mail me and let me know. Anytime. :)

J. R Weems
 

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Denurban -

Not to worry...the 25-06 never gets over 85% load density and the 25 cal bullets displace mostly air when seated deeply. As for your 75 grainers, try to shoot the longest bullet available. Measure length by taking one and inserting it gently in the muzzle of you rifle and turning it back and forth to get an imprint of the lands as a faint ring on the bullet. Choose one where this ring is as far as possible from the base and you will get a bullet that seats as far into the neck for good support when you seat to the lands.
 

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Englander - I would just like to add that the method I use for figuring O.A.L. is the one listed on the Nosler Bullets web site. I've used this method for my .224 Weatherby when I switched to the new 55 grain Nosler Balistic tips and it worked great for me. CEJ...
 

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Englander:

I'm not sure if anyone else has mentioned it, but try IMR 4064 for your propellant. I have been using this powder exclusively for ALL my .308's; and have been using the .308 as my exclusve "30 cal" for about 10 years now. It is an enherantly accurate round for both the hunt and match shooting as I'm sure you are aware of.

I mostly load the 155 Palma or 168 grain Match style bullets for everyday shooting (in the U.S. M14)at paper, loaded to 2.810, the recommended MAG. length for the 14( length also works well with the Rem. and the Win.) but have found that the 165 Hornaday SP shoot VERY well out to 300 yards on the average whitetail in my Winchester model 100, the Remington 700, the Savage 10series and the Browning BLR. For 165 and 168 grain bullets I've been using 42.5grains of IMR 4064.

I just received some of Marshall's 160gc .30cal bullets which I had planned on loading into a 30-30 recipe, but may experiment with the .308 also. They are a flat nosed bullet, so I'm guessing they will not feed too well in my model 100 or the 14.

I wish you well, good luck. Just thuoght I would mention another powder.


Chris from NJ!
 
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