Video On Bump sizing cases.

bigedp51

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I guess I am lucky because I have never had a bolt lug gall. I have seen lugs that were very bad that needed to be leveled and squared to prevent this. when I blueprint an action after leveling and squaring, I polish both surfaces with 1200 or 1500 Garnet lapping compound. This makes the lugs very smooth and prevents galling.

Neck sizing can help prevent this but high pressure loads and heavy bolt lift are the biggest reason that galling occurs.

J E CUSTOM
How can neck sizing and the rear of the case pushing on the bolt face prevent galling the lugs? And how much rearward force does just the ejector apply to the bolt lugs. And why do the vast majority of competitive shooters tell you to full length resize with .001 to .002 shoulder bump?

I will take the word of someone who worked in the Sierra Bullets Ballistic Test Lab and who now shoots for Team Lapua USA.

Click on the image to enlarge.

 

Riflehunter1776

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I'm not going to get involved more. All I will say is that any fool knows that NS cartridges are only ever intended to be used in the rifle that the brass was originally fired out of.
 

bigngreen

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It seems that it's the neck sizing guys who aren't trying stuff, every guy I know got gains by sizing to get .002 headspace also used to neck size.

The cams in an action are not there to cam in a cartridge, just look at all the damage that come from it, they are made for pulling the weight of the spring that's it.
 

Don A Parsons

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At least we have options to try different case sizings or not,,, if your comfortable with the loads your producing,,, then stick with it,,, if your trying to squeeze a little bit more out of it,,, then try something different,,, this is only one of thousands of options...

Maybe rifle H likes loose cartridges,,, K works better with tigther rounds...

I'm sure willing to give this a try...

Another thanks to JE for sharing some ideas on checking all 3 rifle """actions to bolt shank fittment."""

I only see a win win from this thread,,, either I'll see benifits or I won't,,, I see nothing wrong with giving my rifles a check-up,,, and trying some different case sizing scenarios...

Load development is part of my shooting sports,,, this is what some of us reloading folks try and do for our own satisfactions...

PS: like I mentioned in one of my posts,,, sometimes I go the distance,,, other times I just run things through...

All good no matter what out come shows up on the paper from down range,,, squeezing the vertical is a good thing when I want to...

Cheers from the North
 

Don A Parsons

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I'm trying to get the take away on the above video with Brian,,, the KISS ammo thing is a given for those of us that have taken a reloader course and understand the concepts of it as well as putting it into action...

This brings up many more questions on what he shared,,, and what is missing... I'm going to play it again tonight to see what is missing...

Paying attention to some brass prepreation is important along with many other factors,,, not over doing things,,, not leaving out steps that show good results on paper at 100 yards and beyond...

I totally agree with his comments as my good friend has shot along side of Brian...

Take what we know and give things a try,,, it only takes a few bullets down range from our rifles to find out if it improves the groups or not...

Life is simple that way if we choose to test different things for our rifles,,, optics,,, reloads,,, and shooting set-up...

Thanks for the ideas...
 
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Don A Parsons

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I just loaded 30 test rounds using the partial FL sizing thing on shot chambered fitted brass from this rifle,,, they fit like a glove with ZERO tension on the bolt handle with firing pin removed...

Hopefully next week i get a chance to launch them at our range,,, 6 FIVE shot verticals to see if there like a squished peanut butter and jelly sandwich... Ha...

I was suprised that there was solid resistance on the bullets when seating them,,, 0.170 thou at the leed of the neck is the only part that got sized,,, if I would of dropped the FL die any lower it would of started to squish the side-walls of the cases causing the brass to strech forward that would cause resistance when dropping the bolt handle...

Non snugg fitting brass seems very consistent out of my 3 rifles,,, so I'll run with what's working less this 1/2 size FL idea,,, absolutley nothing to lose with the chances of tigther verticals from this rifle...

100 meter warm up,,, followed by the first string,,, a quick jump to 400 followed by a 600 meter... Then run it 1 more time to double confirm the test,,, my guess is that I will see the tightest verticl from this 11.9 lb all in hunting rifle...

Hopefully that is,,, we are going to machine 1 of the quick attach basses for my Remple F class by-pods,,, that way it will eliminate all the variables for the Remmy model 700 BDL stock...

Its my fake back-up F/ PRS/ Hunting rifle,,, yes that I get my @$$ handed to me many times,,, but I get a chance to push the limits of a semi factory rifle to some of the best of the best at some of the matches... LOL...

Just on the edges of a bronze if I can get my BB's lined up on the good days... Ha

Thanks again for the idea JE,,, if it doesn't work out you owe me a coffee with a nip of of the spirits... Ha...

Cheers from the North
 

Don A Parsons

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Bolt to action play is next to nill.. very happy indeed... I'll check it a few more times with the firing pin removed...

Nill for bolt play https://photos.app.goo.gl/2uGs9x9uY5YPDfLz9

My friend re-collared the rear of the bolt for a snugg fit,,, he lapped the bolt lugs before installing the barrel... $100 Cnd funds,,, $70 Usd...

Machined rear collar for snug fit https://photos.app.goo.gl/oxFv11tFeFy9wcy46

I can't wait to give the 30 partial sized cartridges a run for the money... Ha

Hopefully my shooting skills are up to task for this.... I'll mount my F class bypod to get some clean break shots down range...

F class bypod mount. https://photos.app.goo.gl/pjPjGZZfApD3sn62A

Its all about land canon shots on this test...
 

Don A Parsons

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With just the bolt in the receiver it is normal to have .007 to .010 thousandths slack forward and backwards. Some have even more than that depending on how much bolt relief was built in. This is still OK as long as it is not caused by bolt lug set back from hot loads.

When you place a go gauge in the chamber with no firing pin assembly and ejector, the centerline movement should be held to .003 to .004 maximum. Best is .0005 to .0015 in my opinion. After fire forming, it should be .000 and adjusted to what you prefer during sizing. The amount of head space needs to be based on the type of firearm and it's use. When possible, I prefer .000 to .0005 to hold the bolt stationary during firing (No Slack).

J E CUSTOM
Just checked the bolt to action clearance with firing pin re-moved,,, """empty chamber with no brass cases.""" 0.009,,, just under the 0.010 thou mark... I would of liked it tigther,,, but the barrel and head space is set on this rifle...

Looks like its a go JE,,, thanks for the heads up...

Good enough for my hunting rifle,,, my target rifle is at 0.004 with a fitted PT&G bolt from Kipp,,, super cool fellow...

Send him all the dimensions of your action and factory bolt,,, find the snuggest sizing plug that fits into the front and rear of action,,, he will machine a over sized bolt so there is nill for play,,, our job is to do the final fit-ment so it slides like glass in the action...

A """tuned""" smooth bolt shank for jacking in the rounds,,, also ask about the next larger size bolt handle knobb,,, much easier to grab onto in the winter when its cold with the gloves on... definently worth it in my books...

Don
 

Don A Parsons

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It crown land shooting test since the ranges are closed,,, big blue skies to give the partially sized cases from the FL dies a run for the money...

Big chunk of plywood,,, shootings pad,,, solid bunny-ear rear bag and bypod to plant rifle like a land cannon,,, and lots of dry-firing practic between the shots...

Chain saw to gather fire wood,,, make big bon-fire,,, and bring lawn chair along with lots of coffee and a bunch of food,,, smokey dog cook sounds good...

A bit of walking since ill do my first test at 300 meters,,, then confirm the ladder test at distance later...

The summer project of plinking this year,,, a few ideas from brothers JE and Alex for my hunting rifle should smarten it up... Ha...

Hopeful some bear season too...

Cheers from the North
 

Muddyboots

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The one issue that changed how I size brass was the Eureka moment when I realized that brass springback is totally inconsistent within manufacture, within specific lots and from manufacturer to manufacturer. When I switched from using the Stoney Point comparator (that's how old it is) to removing bolt shroud, with firing pin and ejector to close on a fired case without any cam over pressure is when I found out how critical the headspace measurement of the rifle itself was in relation to sizing brass. The headspace comparator is then useful to size brass to what you actually measured from your chamber. If you haven't tried this method, it can be a real eye opener on just what your chamber actually measures and not from brass that has springback all over the map in measurements. I have sorted brass based upon the "springback" measurement to see if they then can be sized more consistently and my answer is yes it appears so.

Like the video says "It works for me" for the distances I tend to shoot which is not LRH by any stretch but still far enough I want to hit the 12 ring on the critter.

You may not agree with everything that is posted on this site BUT what is great is that the threads should give you moments to pause and reflect on your own processes for which I thank everyone here for that opportunity to improve my reloading.
 

Don A Parsons

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Just set my own personal best ladder test with partly neck sized brass using FL die...

Five shot 1/2" ish gathering at 200 meters from a 6.5 A-Square hunting rifle of all things... Ha

Then I run the fired casings threw the chamber with firing pin removed and the bolt handle drops free...

The semi tame loads allowed the shoulders to spring back,,, so I'll do the full-length partial sizing once again...

I knew it would work,,, but I wasnt expecting to end up with a 1/2" vertical at the 200 meter mark... the 5th shot was a flyer,,, thats why I have to run again...



3 powder charges tested

The worst spread was 1 1/16" moa


So I'll do it at 400 and 600 on the next test...
6 Five shot ladders of 30 shots total was just to easy...
 
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JTB

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I have tried every sizing method to assure consistent accuracy and could never make it happen neck sizing. FL with a 0.002 bump is the ticket for me. Consistent neck tension with the correct bushing is a must; I prefer lighter neck tension so that the neck does not mar the jacket when seating. Neck turning is also a must-do step for me. I also measure each case to assure it is a 0.002 bump and sometimes have to give one another partial cycle. I could never to assure each neck-sized case would close with the exact same resistance and if one had more resistance I would get occasional fliers. It is difficult to shoot 1/4 MOA and if shooting outdoors, conditions will make it almost impossible unless I settle on the best of my many 3 shot groups. 5 or more shot groups will give a better indication of where group size is. I attached a picture of a 4 shot group I shot a couple of weeks ago on a calm morning at 300 yards but couldn’t bring myself to take the 5th shot. If you have figured out a process the give consistent results stick with it.
5EE16BC7-02AB-45D0-BC33-F0A39C6433AF.jpeg
 

Don A Parsons

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Me too...

I've never minded doing the shoulder bump till I tried this neck sizing only using my FL die,,, it seem to tighten things up for the hunting rifle...

Reducing the powder charge helped,,, the cartridges must be able to springing back...

Don't know

The reduced loads might be allowing the cases to spring back,,, the bolt handle drops freely with no restrictions at all,,, and talk about accuracy,,, nice to find a simple trick to get this rifle dialed in ...

I knew it would work since I've played with particle sizing using full length dies,,, paying attention to the sides of the cases to prevent the squeezing affect,,, the shoulders don't move forward if I get the die set...

Guess i won't have to fork out more money on a custom sizing die now that my FL die does what I need it to do...

Im glad i give it a try,,, my next trip to the range is to re-confirm that its working,,, pretty happy to pull off a 1/2" moa ladder from this rifle...

Hopefully with out a flier... LOL
 

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