Does a purely sabot rifle barrel need breaking in?

[Blumpy]

This will show exactly how much I know. It's a fact that you break in new rifle barrels... at least I know it to be true of rifles where the bullet itself contacts the lands and grooves. I understand that this is to (oversimplification) in effect smooth out microscopic imperfections in the lands and grooves from the manufacturing processes by the repeated bullets tight fit friction rubbing them out as they pass through said lands and grooves with or without some kind of special rubbing compound made for that purpose.

What about rifles that use bullets encased in hard plastic sabots? The plastic is so much softer than bullet material that it seems to me that either instead of taking approx. 50 rounds to break in a barrel, it would take thousands. OR, that the sabot plastic would be forgiving enough that the barrel imperfections wouldn't affect the bullets flight since it strips off upon leaving the barrel. Eventually the barrel imperfections would be "shined out".

A third option might be to use the break in compound on your sabots just like any other bare bullets. Would the softer plastic of the sabot allow the compound to do its work?

I havn't heard of this being brought up before. Opinions?

I have a Pedersoli Missouri River Hawken Rifle with 30" barrel, 1 in 24 twist, 6 grooves, topped with a 6x old style Malcolm Long Scope. The rifle and scope are off to a gunsmith for proper mounting. It has yet to be fired.

I havn't worked out my load, but it will probably consist of 90 to 115 gr. of Old Eynesford behind a 300 gr. Harvester Muzzleloading PT Gold spire point in their black crush rib sabot.

 

[Fine Figure of a Man]

No IMO but I'm not convinced center fire rifle barrels need it either.
I do have a couple round ball muzzle loaders that cut patches until they had about 100 shots fired.

 

[arcticap]

Some sabot rifles with very tight bores were said to have benefited from polishing with a bore paste, but that's usually done to make loading easier.
And some folks think that it takes a number of shots for even a sabot barrel to break in, but unlike RB barrels they usually don't seem to ever noticeably wear out.

Besides the soft sabot, there's carbon fouling and particles that builds up in a bore that could be creating friction along with the plastic, in addition to the hot gases from blow by.
And there have been products developed which are said to treat the bore to help make fouling easier to remove or are considered to be "molecular' accuracy enhancers.
IMHO there's bound to be some microscopic wear over time which could be considered to be part of a breaking in period, but how much and what causes it if any, is debatable.

I've always been a sort of a sucker about cryogenized barrels which some barrel manufacturers may do as a matter of routine.
But not many advertise that they do it, or state which barrels that they do it to, or if it helps alleviate the need for a break in period.--->>> https://www.300below.com/firearms-cryo-barrel/

 

[243winxb]

Plastic will fill in the voids with a coating, so i don't see an accuracy problem.

Do use a cleaning solvent that will remove plastic.

 

[Loyalist Dave]

You probably will do much better for yourself by trying several different brands of sabot rounds, and powder loads, to improve your accuracy. I don't think the plastic of the sabot against the walls of the barrel will ever polish the steel.

A widely common mistake (imho) of hunters using inlines, is the concept of trying to duplicate the performancde of a modern, smokeless round. Especially since dupliction of that modern round is quite often not needed.

I see fellows using from 120 to 150 grains of black powder, a granular substitute, or pellets. I think that's completely unnecessary at 200 yards or less. While one may have an accurate load with such a high powder load, just because the rifle can take that much, doesn't mean you should load it to that level. So the rifle shoots fine from a bench with 150 grains..., a bench will help you to correct for a flinch, that you might just have from shooting such a stout load. When hunting though..., that flinch will really mess with your success, and you might not realize you have it.

Consider this..., would a .45-70 government cartridge, launching a 300 grain bullet at 1800 fps that was accurate out to 200 yards be a good choice for deer? So why wouldn't an inline shooting 80 grains of powder, that accurately launches a 300 grain bullet in a sabot at 1800 fps be any less effective? The deer won't know the difference, but your shoulder might thank you.

Just my 2₵

LD

 

[Steve S.]

I don’t feel that a BP barrel needs “break in”; more importantly is discovering the powder/ primer/ bullet combo that the rifle likes. I have a T/C Pro Hunter that I have shot for years with 245 grn Powerbelts over 100 grn (2 pellets) of T7 ignited by WW 209 primers. Accuracy was OK sometimes and random at other times; I continued to shoot this combo because it killed deer. Today I went to the range and tried a different combo - 250 grn Shockwave over 100 grn Pyrodex and WW 209. To my amazement, that combo shot one hole clusters at 50 yards - extremely consistent load. I also lost the infamous “crud ring” from the T7 - I still swabbed between shots but had not near the fowling as with the T7. To your question, my barrel was well “broken in” but only shot OK - changing the loading combo made a huge difference.

 

[Captains1911]

It’s a fact that rifle barrels require a break in?

 

[Jackrabbit1957]

There's is gonna be a lot of debate on this one and lot's of different opinions. My personal experiences are with mostly Green Mountain barrels and yes they do need to break in. I found that somewhere around a hundred shots would do it. I like a patch made from .018 canvas duck with a couple of drops of Pinesol for lube/ cleaner. The barrels shoot good out of the box but seem to group better after a hundred or so shots. I would think the same would apply to a sabot barrel as well.

 

[Loyalist Dave]

Is the steel in the sabot barrel the same as that in the Green Mountain BP barrel?
Is the inline sabot barrel polished more than the Green Mountain barrel?
LD