Bore-Ride Bullet Nose Fit?

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.22-10-45 posted this 4 weeks ago

I am kind of new to bore-ride bullets...what I have read is bullet must be a close fit in bore..(land-land) for best results...but what is close fit?  I am just starting to load for an Al Story Sharps Borchardt in .30-40 Krag.  Rifle has a Lilja barrel.  Chamber throat is as close as I can measure .310" dia.  a .310 dia. bullet..checked with Starrett .0001" mic, shows even rub marks all around front band when pushed until stopped by rifling.  a .300 dia. bullet nose shows light land marks ..not full rifling lands..only a thin groove marks..and push feel is a nice firm light press when pushed in muzzle.  Over the years, I have accumulated quite a number of .30 moulds..some cast bullets measure .302-.303 on nose.  These will chamber, but rifling will stop then with rifling marks right at nose ogive.  I have two custom sizer dies made by Buffalo Arms that will size right on .300". & .302" dia.  I am assuming those .303' noses are too large and cause leading?  Any opinions will be greatly appreciated.

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Aaron posted this 4 weeks ago

It should fit without engraving. As close a fit as possible is desirable. This is where different bullet alloy will kick ya in the arse. It should be the perfect fit when cast in the intended alloy.

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Ed Harris posted this 4 weeks ago

Bore-riding to depart should engrave positively when forced into the muzzle, but should chamber with light marking only with slight resistance being felt to bolt closure.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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Wm Cook posted this 4 weeks ago

Chamber throat is as close as I can measure .310" dia.  a .310 dia. bullet..checked with Starrett .0001" mic, shows even rub marks all around front band when pushed until stopped by rifling.

The Freebore sounds perfect as you described it.  If I were a persnickety smart aleck I'd ask if there was a very slight plowing action shown on the front driving band from the freebore wall face shaving the front driving band but the way you described it sounds like a winner to me.

I have no experience in seating depth in a situation like this but the 30-40 looks to have a case neck length of .4851 so my starting depth could be with the bullet base in the bottom of the neck.  What seating depth did you decide to start with?

And heck while I'm asking/learning:

  • what mold are you using?
  • what powders will you start with?
  • what alloy is gonna be used?
  • what velocity are you looking for?

.....nose shows light land marks ..not full rifling lands..only a thin groove marks..and push feel is a nice firm light press when pushed in muzzle.

If you can see the lands and if you can feel the slight drag as the nose slides into the bore I would not ask for more.   To the tenth of a thousandth what does the nose measure exactly?  What does your bore measure?  Fresh lands are normally .004 so engaging them well without sticking would be the direction i'd head.  And like Aaron suggested, you have a couple, three tenth of a thou to gain between Lyman #2 and Linotype. 

Never had luck feeling bolt closure on cast bullets with a bolt that wasn't stripped.  The same resistance you feel when the front driving band reaches the lands upon bolt closure (full forward position before bolt closure) is a seating depth to consider if the base of the bullet is where you want it in the case neck.  Just an opinion.  Not gospel.  Bill C.

 

 

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.22-10-45 posted this 3 weeks ago

I have a dozen .30 rifle moulds picked up over the years, and a few since purchasing this rifle...so finding all the accurate combinations of bullet/powder will probably not be completed in my lifetime!  I have so far loaded & shot 3...two are single cavity Ideals, 311291 & 31141.  Alloy is 20# Wheel wt. & 2# 50-50 Solder dipper pour.  Bullet lube is home brew. All bullets sized to .310". Nose on the291 is .302" the 31141 nose is undersize to a point about .06" ahead of front band and will show land marks pushed in muzzle at this point. When chambered, 311291 shows land marks on nose, 31141 contacts rifling leade but shows no engraving.

    This is a modern made model 1878 Sharps Borchardt.  My method of determining o.a. seat depth is to seat bullet long in dummy case & to just be able to close action with minimum resistance..nose is usually lightly engraved and breech block pushes case to final seat as closed.  Even though engraving is hardly felt...and seen on nose, when chambered, extracting bullet/case requires firm pressure on lever..though bullet seat depth does not change.

    Last Sat. was my first time out to range this year, and first time out with new to me rifle.  Previous owner stated he had shot 100 rnds thru..all jacketed, and said he had gotten quite a few 1" at 100yd groups.

    I decided to save time, so I loaded at range.  I use pre-measured charges in 1ml. amber glass vials with screw tops.  sizing & priming done at home..only charging & bullet seating at range. I have a near mint Ideal nickle tong tool that is a joy to use and a dial caliper.  Get some strange looks as most of these guys don't reload.

   Set up on 100yd. 1st. up was the #291..start load was a light 15grs. of H4227, had to use 3 for bore-sight as I had mounted a Leupold 12X fixed with dot over winter.  1st. 3 went into little cloverleaf each cutting into each other..now thats not supposed to happen!  further testing would give 2 or or sometimes 3 cutting into each other...but others were fliers opening groups to 5/8" to 1 1/8".  Increasing charges didn't help until I reached 17grs...groups closing up and round.  At 18.5grs. I got a 1/2"X 1/4" group of 5 shots.  This charge was also the most accurate in an 1898 Krag military about 20 some years ago when I could still see irons.  Using 19.grs groups started to open up.  

    The other bullet I tried was the Saeco #315.  This is a tapered bullet with only the base band at .311  This showed promise right from the start with 15.gr. H4227.

     I am now wondering if I missed a low velocity sweet spot with that 15gr. start load..so next time out I will try 12-14.5gr, H4227.  I have charges made up of Rel. 7 as this has proved to be a good cast bullet powder. I had never before used my home made lube on anything but BPCR type bullets .38 & .40 with light charges of smokeless, but there wasn't a particle of lead after all this shooting.

    All this takes time...I spent 5 hours shooting and probably should have quit sooner.  Also for next time, I have sized some of the 311291 noses to .300"  these are a nice tool room fit in muzzle we shall see...

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John Alexander posted this 3 weeks ago

Interesting post. I look forward to reading about your further testing to find the best load. 

As you tried the string of 4227 from 15 to 19gr, was the interval between loads 0.5 grain?  How many five shot groups did you fire at each load level?  What case is your Borchardt chambered for? I have always thought I needed one but never had the opportunity to buy one.

John

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.22-10-45 posted this 3 weeks ago

Caliber is .30-40 Krag.  I didn't think those light loads would shoot so I went up in 1gr. steps until 17.grs..then .5gr.  3shot groups to see if there was promise..5shot if there was.

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John Alexander posted this 3 weeks ago

Thank you.

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.22-10-45 posted this 2 weeks ago

Well, my hunch was right...I had missed a low velocity sweet spot first time out with rifle on June 4.  Last weekend I set up at 100yds with pre-measured loads of H4227 from 12.0gr. thru 14.5gr. just to cover light load bases I might have missed.  Sure enough, 14.0gr. with the Ideal 311291 s.c. printed groups of 5/8" X 3/8"...14.5 just about the same..perhaps just a might larger, but hard to measure.  14.0gr. with the Ideal 31141 printed a 1/2" X 3/8".  These 14.0-14.5 gr. loads are a pure pleasure to shoot.   Re-tested the 18.0gr. load of H4227 with Ideal 31141 & got a 1/2"X 3/4" group. about the same with the 311291.  This rifle likes cast!  The fellow I purchased it from said he had put 100rnds. thru and had gotten a few 1" groups at 100yd.  I don't know if they were factory or handloads, but bore didn't show any copper fouling.

   He said he had it built for hunting..and it isn't the easiest gun to shoot off sandbags, forend checkered on sides bottom smooth..but rounded, plus there are sling swivel studs to contend with.  I found if I position buttstock so stud just touches back of rear Protector bag & front stud is about 1" in front of front rest bag, I can slide gun forward until stud touches rear bag & crosshair is just a touch high..a slight bag squeeze brings it down to target.

    Last weekend I also tried for first time a Hoch nose-pour .310177..looks alot like the 311291 with longer nose.  As cast nose was .302" & didn't even begin to fit muzzle.  I ran them nose first to 1st. band in a custom BACO .301" Lyman style die...nice snug fit in muzzle, lands just lightly engraved nose as action closed.  I had by this time ran out of the 14.0 & 14.5gr loads, so I tried 18.0gr H4227.  Grouped 3/4"X5/8"...18.5 grs. group opened up a bit.  Next time this one gets the light load test.

    When I bought this gun, I fiqured it would keep me busy for the rest of my shooting career...well it's doing a good job..I need to cast more bullets!

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